第二章 代数式(举一反三讲义)全章题型归纳
2024
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1 !"#$ ....................................................................................................................4
2 % ........................................................................................................................................6
3 & ................................................................................................................................................8
4 '( ..........................................................................................................................................10
5 )*)+,- ......................................................................................................................11
6 ./01234 ..................................................................................................................................13
7 5.617 ......................................................................................................................................15
8 )89:;<=>'( ..................................................................................................................16
?@ .................................................................................................................................................................18
9 ABCDE'( ..................................................................................................................18
10 FGDHE'( ..................................................................................................................21
11 #IJK ......................................................................................................................................24
12 )89EL4M ..................................................................................................................27
13 )89ENOPM ..................................................................................................................29
14 )89QRST ..........................................................................................................................33
15 <UV(+=> ..........................................................................................................................37
16 JW<XY#I.Z[=31 ......................................................................................................40
17 JW<XY#I.DH[=31 ......................................................................................................42
知识点1 用含字母的式子表示数
TZ\]^+Z\_X`abcdefghijakKlmnopqrs
T^Z\_X`!"#t
.11Z\<Z\vwxd“ × ” {|}~"]"“ ⋅”
.21Z\<vwxd{|"Z\
.31l<Z\vwxd{|=le
.41Z\<Z\vxd"Hs
.51_eFa]HdOlxd_)87 s
知识点2 代数式的概念
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T:; ]X`Z\m_s]Z\s
0da
¡s
知识点3 代数式的意义
¢£¤¥QR¦§%T¨©ª«¬md¦Z\*:; ®¯°^s
知识点4 列代数式
><b+±¨TX`¬m&s
TX`
a < a 95 b ²d
³E:;±“”X`bc a 95 bd&_e a-b:;±“²”X`bc a µ
“”d¶
𝒂
𝒂−𝒃.·¸)1s
知识点5 代数式的值的概念
T(¹EZ\dº»E:;c¼;½¬Od(s¾¿A
'(s
𝑥= −5xd(𝑥+ 2)2 = (−5 + 2)2 = (−3)2 = 9dÀÁ 9 𝑥= −5xd
(𝑥+ 2)2(s
知识点6 求代数式的值的步骤
'(+Ãa¼;ÄÅs
ÆÅ
T(¹ÇZ\d>ȓÔsÃxd¦vSZ\Éʧ]Ê;¬m
(d³Ë:; ÌmZ*:;ÍB¡~Î[s
ÆÏÅ
º»E§¬:;d¼;¬Od>È“¼;”sÃ(~2dÐi¼;¬OÑ
Ò~2s
知识点7 单项式
1.
]Z\ÔdÀÁ¾4s]Z\
4s
2.4c
4EZÕ¾4cs
3.4Ö
4Ed×+Z\Øa¾4ÖsVÙÚÛd#
ÜÖe 0s
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知识点8 多项式
1.
F4aN4s
2.N44
N4EdÝ4N44d³E~^Z\4|4dN4^
+F4dF4s
3.N4Ö
N4ÇdÖÐÞ4Öd¾N4Ös
知识点9 整式
1.
4<N4ßÈ)s
2.4 N4<)cD×`s
3. àá) 4*N4qâ
.114~^89:;dN4ã^89:;
.21N4F4adN4~ä^4
.314aN4¡)d\E^+Z\¡~)s
知识点10 同类项
×^Z\v2d0v2Z\Øv24234sF|4234s
知识点11 合并同类项
N4E234/04d/0234s/0234id×½4c/0å234c
adZ\2ÜØ~[s
/0234æÅç
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知识点12 去括号
1. 57 qâ
æèd<N4vwdé57 d57 T7 êw7 ëÝ4dì×½
Ôv8s7 êwíd57 iÌ7 ëå4 <Ìm v27 êw
îd57 iÌ7 ëå4 <Ìm vïs
2. ð£
ñI a(b+c)=ab+ac.
3. Nò7 5â
æóëôêdõ5ö7 dì5E7 dÐi5p7 s
知识点13 整式的加减
)89:;ât
F)v89d+7 õ57 d÷iì/0234s
ST)89:;ât=>'(xdæõ57 /0234dìÃZ\(øù¼;d>úe“
= Ï û¼;”s°:;Edѵõ¦234/0dì57 düº:;ÍB5ýsd
−2(𝑥−3𝑥+ 5𝑥−7𝑥+ 6) = −2(−4𝑥+ 6) = 8𝑥−12s
【培优篇】
【题型1 代数式的定义、书写规范】
1_ n﹣3 a2b m+s≤2 x ﹣ah sþab E+.ÿÿ1
As6
Bs5
Cs4
Ds3
ĀāC
öT:; <Z\m_dð£ă%'Ąs
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ąĄÕe¶T:; <Z\m_d×µ n﹣3 a2b x ﹣ah ¡d×µ
+ 4 sĆć Cs
ĈĉĊċČčĈ
sĎĄ%ďs
[ 1-1.24-25 ĐđĒē·Ĕĕ·ĖE1ė&!"∶①−1𝑎②2
2
3𝑎2𝑏③
5𝑎2𝑏
3 ④𝑏
2
3⑤2024 × 𝑎× 𝑏
⑥𝑎+ 3 ĘęEdíĚ+
s.·"B ¶Ñ1
Āā③
ĂěĊĜ!"#$d¢£Z<Z\ĝĞw }~"dZZ\id"
dN4<ĝĞ87 ğàá¶Ñ½ĠĀā
ąĄĄ
−1𝑎S"−𝑎d~/%d
2
2
3𝑎2𝑏S"
8
3𝑎2𝑏d~/%d
5𝑎2𝑏
3 !"#$/%d
𝑏
2
3S"
2
3𝑏d~/%d
2024 × 𝑎× 𝑏S"2024𝑎𝑏d~/%d
𝑎+ 3ĘęS"(𝑎+ 3)Ęęd~/%d
ĆĀāe
③s
[ 1-2ė&åEd~.ÿÿ1
As3a
Bs0
Cs2xþ1
Ds𝑎2−
𝜋
16
ĀāC
Ă¢£ğ4àás
ąĄA 3a d~/%
B 0 d~/%
C 2xþ1 qAd~d/%
D 𝑎2−
𝜋
16d~/%
Ćć
Cs
ĈĉěġĊĜndíĚĢĄďs
[ 1-3ė&å
3ad1
2
3ad
b
5da × 3d3x−1d2a ÷ bd³E/!"'+. 1
As1
Bs2
Cs3
Ds4
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ĀāC
Ă¢£!"'àáå¶Ñs
ąĄĄ
3ad
b
5d3x−1íĚ
1
2
3aS!"e
5
3a
a × 3S!"e3a
2a ÷ bS!"e
2a
b
×µ/!"'ģ3d
Ćć
Cs
ĈĤěġĊĜn!"d!"'
(1)E¬ĥw d{|>"“•”]
Ħ}~"(2)Z<Z\vwxdZ"Z\(3)E¬ĥâ:;d溻
"âm"sl"Hs
【题型2 代数式的意义】
2.24-25 ĐđĒē·ħĨĩĪ·ĖE1²īV²ĬĭĮøùįěİı¥IJdİıqâ¦ěe𝑥ij
²ĬĴĵ50%iĶĵdìµ(0.9𝑥−30)ijİıĵ¬ķdtė&ĸâEd①Ķĵ95 30 ijiìĹ 9 ĺ②
ĶĵĹ 9 ĺiì95 30 ij③Ķĵ95 50 ijiìĹ 6 ĺ④ĶĵĹ 6 ĺiì95 30 ijsÒíĚXYĻ
²īİıqâ
s.·B 1
Āā③④/④③
ĂăġĊĜnděe𝑥ij²ĬĴĵ50%iĶĵe(1 + 50%)𝑥= 1.5𝑥dļ&¬Ľĸ
âİıĵdìÑàá¶Ñs
ąĄĄ
ěe𝑥ij²ĬĴĵ50%iĶĵe(1 + 50%)𝑥= 1.5𝑥d
①Ķĵ95 30 ijiìĹ 9 ĺdtİıĵe
(1.5𝑥−30) × 0.9 = 1.35𝑥−27 ≠0.9𝑥−30d
Ć①~/
②ĶĵĹ 9 ĺiì95 30 ijdtİıĵe
0.9 × 1.5𝑥−30 = 1.35𝑥−30 ≠0.9𝑥−30d
Ć②~/
③Ķĵ95 50 ijiìĹ 6 ĺdtİıĵe
(1.5𝑥−50) × 0.6 = 0.9𝑥−30d
Ć③/
④ĶĵĹ 6 ĺiì95 30 ijdtİıĵe
0.6 × 1.5𝑥−30 = 0.9𝑥−30d
Ć④/
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ľēdÒíĚXYϲīİıqâ③④s
ĆĀāe
③④s
[ 2-1.24-25 ĐđĒē·Ŀŀ|Ł·Ėł1öŃ¢£qA5𝑥+ 10(𝑥−5) = 400ń"nŅSTdņŇ
ňʼnŊŋŌ¸)sō ŎÄŏŐő¤ŒÛœdÊČōŐőÝŔŕŎŐőN¤Œ 5 Ûœd
dņ
MōŐőÝŔ¤ŒNŖÛœŗ.ŘōŐőÝŔ¤Œ𝑥Ûœ1
ĀāōŐőŐ 5 ŔdŎŐőŐ 10 Ŕdģ¤Œn 400 Ûœ
ĂěĊĜnijÖqASTsàá¬vSřbcXQR%ĄŚMďs
ĂqAå4%d¶ÑĄĀs
ąĄĄ
ÕeŘōŐőÝŔ¤Œ𝑥ÛœdtŎŐőÝŔ¤Œ(𝑥−5)Ûœd
×µqAE5𝑥X`ōŐő 5 Ŕģ¤ŒÛœbd
10(𝑥−5)X`ŎŐő 10 Ŕģ¤ŒÛœbd
Ć5𝑥+ 10(𝑥−5) = 400X`ōŐőŐ 5 ŔdŎŐőŐ 10 Ŕdģ¤Œn 400 Ûœs
ĆĀāe
ōŐőŐ 5 ŔdŎŐőŐ 10 Ŕdģ¤Œn 400 Ûœ
[ 2-2.24-25 ĐđĒē·śŜŝŞş·ĖE1ō Ŏ2Ù“2(𝑥+ 𝑦)”%ª«dàáíĚ
. 1
ō
𝑥2Š<𝑦a
Ŏ
šÝĘę𝑥ijdŢţÝĘę𝑦ijdšaŢţåŤ2ĘęťŦŧ
AsŨ+ōíĚ
BsŨ+ŎíĚ
Csō Ŏ¡íĚ
Dsō Ŏ¡~íĚ
ĀāB
ĂěĊĜn%d¢£ō Ŏ2ª«&¬dìøùàá¶Ñ'ĄdĎĄ
%Ąďs
ąĄĄ
𝑥2Š<𝑦a2𝑥+ 𝑦d×µō2ª«ũŪ
šÝĘę𝑥ijdŢţÝĘę𝑦ijdšaŢţåŤ2ĘęťŦŧe2(𝑥+ 𝑦)ijd×µŎ2ª«íĚ
Ćć
Bs
[ 2-3.24-25 ĐđĒē·ūŬŭŮ·ĖE1Ù8𝑥−3𝑦X`%dė&ĸâíĚ. 1
Asů𝑥X`ŰűŲĵųd𝑦X`ŴŵŶĵųdt8𝑥−3𝑦X`Ť 3 ŰűŲa 8 ŴŵŶģŦ
nNŖŷ
BsůŸqHŸe𝑥dŹe 8díqHźŸe𝑦dt8𝑥−3𝑦X`ŸqHÔ< 3 íqH
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Ô
CsŻżÝöxùŽ𝑥ĘždſżÝöxùŽ𝑦Ęždt8𝑥−3𝑦X`ſżùŽ 3 öx௿ùŽ 8
öxŖùŽƀA
DsöžÝĘę𝑥ijdpžÝĘę𝑦ijdt8𝑥−3𝑦X`Ť 8 ĘępžŕŤ 3 ĘęöžŖŦŷ
ĀāC
ĂěĊĜ%dĎĄ%Ąďs¢£X`QR%qâğ4à
á¶Ñs
ąĄĄ
A ů x X`ŰűŲĵųdy X`ŴŵŶĵųdt8𝑥−3𝑦X` 8 ŨűŲŕ 3 Ŵ
ŵŶNŦnNŖŷdĆěć4ũŪ
B ů x X`ŸqHŸd8 X`ŸqHŹdy X`íqHźŸdt8𝑥−3𝑦X`ŸqHÔ
< 1 íqHûźŸdĆěć4ũŪ
C ŻżÝöxùŽ x ĘždſżÝöxùŽ y Ęždt8𝑥−3𝑦X`ſżùŽ 3 öx௿ùŽ 8 ö
xŖùŽƀAdĆěć4íĚ
D öžÝĘę x ijdpžÝĘę y ijdt8𝑥−3𝑦X`eŤ 8 ĘęöžŕŤ 3 ĘępžNŦŷd
Ćěć4ũŪs
Ćć
Cs
【题型3 列代数式】
3.24-25 ĐđĒē·ħĨƁƂ·ƃƄƅj1ƆƇƈƉƊƋÔ#te
ŕƋEµ3−0.ƌ 3 ƍî 0 ƍ1
]Ħ3−1ƎƌƊƏÔ 3 dîƏÔ 0 ŕƋEµ3−2ƎƌƊƏÔ 2 dîƏÔ 1 sůƐƊƏµ3−1
ƌn a Ƒdµ3−2ƌn b Ƒdµ2−3în c Ƒdt¾ŰƊƏÔTN4ѵX`e s
Āā3𝑎+ 2𝑏+ 𝑐
ĂěġĊĜn&d¢£Ô#t&¶Ñs
ąĄ∵ƐƊƏµ3−1ƌn a Ƒdµ3−2ƌn b Ƒdµ2−3în c Ƒd
∴¾ŰƊƏÔTN4ѵX`e3𝑎+ 2𝑏+ 𝑐s
ĆĀāe
3𝑎+ 2𝑏+ 𝑐s
[ 3-1.24-25 ĐđĒē·ēƒ·ĖE1TX`“𝑥2
1
395𝑦” s
Āā
7
3𝑥−𝑦
ĂăĊĜn&dµ*!"#$¢£%õ'Ši'd&¬d¦l
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"H¶Ñ'Ąs
ąĄĄ
TX`“𝑥2
1
395𝑦”2
1
3𝑥−𝑦=
7
3𝑥−𝑦s
ĆĀāe
7
3𝑥−𝑦s
[ 3-2.2025·ƓƔƕƖ·ƗƘƙƚ1ƛƜeƝEƞƟßƠĞơ°dóƛ¸ƢƣƤƜa
EĞƥƦƧd³ƨƩDѵƪƛƫƬƭƮĞƯƣƤƜdD×`důvưÄƤƜĝ
ĞƱƲŊŹƳƴe adƤƜƥƵe bdt)ƛƜŹƳѵX`e
s.T^ adb
X`1
Āā9𝑏−8𝑎
ĂěĊĜDH#I3dƶƅƷĢƱƲiŸƳdƱƲŊŸƳd0ƉŸƳcĄďs
TƛƤƜŸƳ95ƱƲŊŸƳ¶Ñs
ąĄĄ
)ƛƜŹƳѵX`e9𝑏−8𝑎s
ĆĀāe
9𝑏−8𝑎s
[ 3-3.24-25 ĐđĒė·Ƣƞ·ĖƸ1ƹƺƻƼÆƉ+ a ƽdÆÏƉ+(𝑎+ 2)ƽdÆ
ûƉ+(𝑎+ 4)ƽdiÝƉŕƉN 2 ƽsÆ n Ɖ+.ÿÿ1ƽs
As 𝑎+ 2𝑛
Bs 𝑎+ 2(𝑛−1)
Cs2𝑛
Ds 𝑎+ 2𝑛+ 2
ĀāB
Ăð%dƾƿǀÆƉ+ a ƽdÆ𝑛Ɖ<ÆƉv𝑛−1ƉdǁiÝƉŕƉN 2 ƽd
×µÆ𝑛ƉŕÆƉNƽe
2(𝑛−1)d¶ÑĀěĊĜ#IǂTdď#IťOaǃDŽǂTd
ăDžƱdžLJťO
ąĄĄ
óČdƾƿǀÆƉ+ a ƽǁiÝƉŕƉN 2 ƽ
Æ𝑛Ɖ<ÆƉv
𝑛−1Ɖd
∴Æ𝑛ƉŕÆƉNƽe
2(𝑛−1)
∴Æ𝑛Ɖƽe
𝑎+ 2(𝑛−1)
Ćć
B
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【题型4 代数式求值】
4−2𝑎2 +3𝑏+ 8(e 1dÀÁ4𝑎2−6𝑏+ 2(řÙ. 1
As14
Bs16
Cs18
Ds20
ĀāB
ĂěġĊĜn'(dLjT)ÃljNJ'ĄĄďsõ¢£%½Ġ2𝑎2
−3𝑏= 7dìó4𝑎2−6𝑏+ 2 = 2(2𝑎2−3𝑏) +2øù'Ą¶Ñs
ąĄĄ
∵−2𝑎2 +3𝑏+ 8 = 1d
∴2𝑎2−3𝑏= 7d
4𝑎2−6𝑏+ 2 = 2(2𝑎2−3𝑏) +2d
¦2𝑎2−3𝑏= 7ý
Ì = 2 × 7 + 2 = 16d
Ćć
Bs
[ 4-1.25-26 ĐđĒē·Ƣƞ·Njƚ1öѼ;41−𝑁xdŪ¦“−”ƪ“ + ”dO½ 13dt41−𝑁
(e. 1
As−28
Bs32
Cs69
Ds−54
ĀāC
ĂěġĊĜn'(d¢£ũŪ;â'¬𝑁(Ąďsõ¢£ũŪ;â'¬𝑁(d
÷iìÃøùíĚ¼;s
ąĄĄ
öŃŪ¦“−”ƪ“ + ”d½ĠũŪř
41 + 𝑁= 13
Ą½
𝑁= 13−41 = −28
∴41−𝑁= 41−(−28) = 41 + 28 = 69
Ćć
Cs
[ 4-2.24-25 ĐđĒē·njŬŬǍ·Ėł1ů(3−𝑚)2 + |𝑛+ 2| = 0dt𝑚2 + 𝑛3(e. 1
As17
Bs−17
Cs1
Ds−1
ĀāC
ĂěĊĜ'( ƬqaUV(ÚîǎdǏLjTÚîǎǐ'ĄĄĀďs¢£
ƬqaUV(Úîǎ'½ m n (dì('Ą¶Ñs
ąĄĄ
∵(3−𝑚)2 + |𝑛+ 2| = 0d(3−𝑚)2 ≥0d|𝑛+ 2| ≥0d
∴3−𝑚= 0d𝑛+ 2 = 0d
Ą½𝑚= 3d𝑛= −2d
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∴m2 + n3 = 32 + (−2)3 = 9−8 = 1s
Ćć
Cs
[ 4-3.24-25 ĐđĒē·śŜǑǒ·Ėł1ŞǓǔÐõT𝑓(𝑥)mX`Ù x N4sVÙ𝑓(𝑥)
= 𝑥+ 1
𝑥= −2xdt𝑓(−2) = (−2) +1d𝑥= 𝑎xdt𝑓(𝑎) = 𝑎+ 1sů#𝑓(𝑥) = 𝑥+ 3dė&OP
E
①𝑓(−1) = 2②ů𝑓|𝑥| = 4xdt𝑥=± 1③𝑥= −3xd7−|𝑓(𝑥)|(e 7µēOP~íĚ
+. 1
As0
Bs1
Cs2
Ds3
ĀāA
ĂěĊĜ'(d①¦𝑥= −1Ã𝑓(𝑥) = 𝑥+ 3dÑ'Ą②¢£%½ĠqA|𝑥| +3 = 4d
ĄqA¶Ñ'Ą③¦𝑥= −3Ã7−|𝑓(𝑥)|¶Ñ'Ąs
ąĄĄ
∵𝑓(𝑥) = 𝑥+ 3d
∴①𝑓(−1) = −1 + 3 = 2dĆ①íĚ
②ů𝑓|𝑥| = 4xd¶|𝑥| +3 = 4d
)Ď½|𝑥| = 1d
∴𝑥=± 1dĆ②íĚ
③𝑥= −3xd7−|𝑓(𝑥)| = 7−|𝑓(−3)| = 7−|−3 + 3| = 7dĆ③íĚ
ľēd①②③¡íĚd~íĚ+ 0 s
Ćć
As
【题型5 整式及整式有关的概念】
5.24-25 ĐđĒē·śŀ²Ǖ·ĖE1N4(𝑚−4)𝑥|𝑚−2| +𝑥−5Ù𝑥ÏÖû4dt𝑚Ǝ(e
. 1
As0
Bs4
Cs4 ] 0
Ds-4 ] 1
ĀāA
ĂěġĊĜnN4dƶƅƷĢN4Ö
N4EÐÞÖ4ÖdýN4Ö
N4+F4F4Ąďs
¢£N4½|𝑚−2| = 2𝑚−4 ≠0d'Ą¶Ñs
ąĄĄ
∵N4(𝑚−4)𝑥|𝑚−2| +𝑥−5Ù𝑥ÏÖû4d
∴|𝑚−2| = 2𝑚−4 ≠0d
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∴𝑚= 0d
Ćć
As
[ 5-1.24-25 ĐđĒē·śŀǖǗī·ĖE1ė&_
−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2d
𝑎+𝑏
2 d
1
2−𝑥d³
EǘÙ4
dǘÙN4
dǘÙ)
s
Āā
−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2
𝑎+𝑏
2
−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2d
𝑎+𝑏
2
ĂěĊĜ4 N4 ),-dĄďǙĚĎĄ0ð£¾ǚ,-mV§_ø
ù3s
①ð£4Ǜ¬4
②ð£N4Ǜ¬N4
③¢£)ä^4aN4Ě)s
ąĄ①4]Z\Ôǜd]Z\ý4d
−
1
3d
𝑎
3
1
3<Z\𝑎Ôd−πd−5𝑥2𝑦3 5 <Z\ xdy Ôd2𝑥𝑦2 2 <Z\
xdy Ôd×µ4−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2
②F4aýN4d
𝑎+𝑏
2 =
𝑎
2 +
𝑏
24
𝑎
2<
𝑏
2ad×µN4
𝑎+𝑏
2 dĆ.21Dž·
𝑎+𝑏
2
③)e4aN4ßÈd×µ)−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2d
𝑎+𝑏
2 d
ĆĀāe
①−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2
②
𝑎+𝑏
2
③−
1
3d
𝑎
3d−πd−5𝑥2𝑦3d2𝑥𝑦2d
𝑎+𝑏
2
[ 5-2ė&ĸâEíĚ. 1
AsN4−
3𝑥2−5
4
|4
5
4dÏÖ4c−
3
4
Bs4−5𝜋𝑥𝑦2𝑧3caÖļ−5d7
Cs
𝜋
2~4
Ds𝑥3 +𝑥𝑦2−𝑦3 +2𝑥2𝑦º𝑦ǝǞƉ&e−𝑦3 +𝑥𝑦2 + 𝑥3 +2𝑥2𝑦
ĀāA
ĂěĊĜnN4d4d¢£4aN4%dğàá¶ÑĄĀs
教辅资源,关注公众号★全科AA+
ąĄĄ
A N4−
3𝑥2−5
4
|4
5
4dÏÖ4c−
3
4děć4íĚd/%
B 4−5𝜋𝑥𝑦2𝑧3caÖļ−5𝜋d6děć4ũŪd~/%
C
𝜋
24děć4ũŪd~/%
D 𝑥3 +𝑥𝑦2−𝑦3 +2𝑥2𝑦º𝑦ǝǞƉ&e−𝑦3 +𝑥𝑦2 +2𝑥2𝑦+ 𝑥3děć4ũŪd~/%s
Ćć
As
[ 5-3ÊČN4−7𝑎𝑚𝑏𝑛+5𝑎𝑏2−1.𝑚d𝑛eí)𝑎Ø~v21º𝑎ǝǞƉ&ĽÖû
4dt(−𝑛)𝑚(e. 1
As−1
Bs3 ]−4
Cs−1] 4
Ds−3] 4
ĀāC
ĂěġĊĜnN4,-dF4aýN4dÝ4ýN44d³E
~^Z\4ý|4sN4EÖÐÞ4ÖýN4Ös
¢£N4*ǝǞƉ&ѽ𝑚> 1d𝑚+ 𝑛= 4d¶Ñ'Ą mdn (dìļü;Ñ'Ąs
ąĄĄ
ó%½
𝑚> 1d𝑚+ 𝑛= 4d
×µ𝑚= 2d𝑛= 2]𝑚= 3d𝑛= 1d
𝑚= 2d𝑛= 2xd(−𝑛)𝑚= (−2)2 = 4
𝑚= 3d𝑛= 1xd(−𝑛)𝑚= (−1)3 = −1s
Ćć
Cs
【题型6 (合并)同类项】
6.24-25 ƛđĒė·śŀNjǟ·ƃƄƅj1ůÙ b 4𝑏𝑚<𝑛𝑏2024v8řÙ 0dt𝑚𝑛
s
Āā−2024
ĂěĊĜ/0234dƶƅƷĢ234Ąď
¢£234“×^Z\v2d0v2Z\Øv2”¶Ñ'¬Āās
ąĄĄ
ó%ÑČ
𝑏𝑚<𝑛𝑏2024234a 0d
∴𝑚= 2024d𝑛+ 1 = 0¶𝑛= −1d
∴𝑚𝑛= 2024 × (−1) = −2024d
ĆĀāe
−2024s
[ 6-1.24-25 ĐđĒē·Ƣƞ·Ėł1ė&åǜ_E234.ÿÿ1
As𝑎𝑐<𝑎𝑏
Bs3𝑎<5𝑎2
Cs3𝑎𝑏2<5𝑎2𝑏
Ds𝑎2𝑏<−𝑏𝑎2
教辅资源,关注公众号★全科AA+
ĀāD
ĂěĊĜ234dĄďíĚĎĄ234děǘÙǠǡs
×^Z\v2d0v2Z\Øv2d¾ƣ4ý234s
ąĄĄ
A ×^Z\~v2d~234dĆ A ć4~/%
B v2Z\Ø~v2d~234dĆ B ć4~/%
C v2Z\Ø~v2d~234dĆ C ć4~/%
D /234d234dĆ D ć4/%
Ćć
Ds
[ 6-2.24-25 ĐđĒē·ŜǢ·ĖE1ņ"¬<−𝑎𝑏2e234)
s
Āā8𝑎𝑏2.Āā~ǣ1
ĂěĊĜn234ČčsƶƅƷĢ234“×^Z\v2dv2Z\Øv2”dĄ
ďs
¢£234EÄ“v2”
.11×^Z\v2.21v2Z\Øv2d!"¶Ñd%234
<Z\ÍBLs
ąĄĄ
8𝑎𝑏2dĀā~ǣs
ĆĀāe
8𝑎𝑏2.Āā~ǣ1s
[ 6-3ÊČ−5𝑎2𝑚𝑏a8𝑎6𝑏3−𝑛234dtė&åǜE4234. 1
As−𝑥𝑚𝑦2<
1
2𝑥2𝑦𝑛
Bs2𝑥𝑚−1𝑦2<0.01𝑥2𝑦𝑛
Cs𝑥3𝑦4<−4𝑥𝑚+1𝑦𝑛+2
Ds−𝑥2𝑚𝑦4<6𝑥6𝑦𝑛+1
ĀāB
ĂěġĊĜn234s×^Z\v20v2Z\Øv24ý234sƷĢ2
34Ąďs
¢£v2Z\Øv2&qA'¬ m a n (d÷i좣234ğ4à¶Ñs
ąĄĄ
∵−5𝑎2𝑚𝑏a8𝑎6𝑏3−𝑛234d
∴
2𝑚= 6
3−𝑛= 1
d¶
𝑚= 3
𝑛= 2
d
∴As ó−𝑥𝑚𝑦2 = −𝑥3𝑦2d
1
2𝑥2𝑦𝑛=
1
2𝑥2𝑦2dt−𝑥𝑚𝑦2<
1
2𝑥2𝑦𝑛~234d~/%
Bs ó2𝑥𝑚−1𝑦2 = 2𝑥2𝑦2d 0.01𝑥2𝑦𝑛= 0.01𝑥2𝑦2dt2𝑥𝑚−1𝑦2<0.01𝑥2𝑦𝑛234d/%
Cs ó𝑥3𝑦4d−4𝑥𝑚+1𝑦𝑛+2 = −4𝑥4𝑦4dt𝑥3𝑦4<−4𝑥𝑚+1𝑦𝑛+2~234d~/%
教辅资源,关注公众号★全科AA+
Ds −𝑥2𝑚𝑦4 = −𝑥6𝑦4d6𝑥6𝑦𝑛+1 = 6𝑥6𝑦3dt−𝑥2𝑚𝑦4<6𝑥6𝑦𝑛+1~234d~/%s
Ćć Bs
【题型7 去(添)括号】
7.24-25 ĐđĒē·śŜǤƫ·ƃƄƅj1ė&57 íĚ. 1
As𝑎+ (𝑏+ 𝑐) = 𝑎𝑏+ 𝑐
Bs𝑎2−−(−𝑎+ 𝑏) = 𝑎2−𝑎−𝑏
Cs𝑎+ 2(𝑏−𝑐) = 𝑎+ 2𝑏−𝑐
Ds𝑎−(𝑏+ 𝑐−𝑑) = 𝑎−𝑏−𝑐+ 𝑑
ĀāD
ĂěĊĜn57 âtSTdÒƶú57 âtĄăďs¢£57 âtğøùà
á¶Ñs
ąĄA 𝑎+ (𝑏+ 𝑐) = 𝑎+ 𝑏+ 𝑐düć4"e𝑎𝑏+ 𝑐dũŪd~/%
B 𝑎2−−(−𝑎+ 𝑏) = 𝑎2−[𝑎−𝑏] = 𝑎2−𝑎+ 𝑏düć4Oe𝑎2−𝑎−𝑏d ũŪd~/%
C 𝑎+ 2(𝑏−𝑐) = 𝑎+ 2𝑏−2𝑐düć4"e𝑎+ 2𝑏−𝑐dcʼnǥdũŪd~/%
D 𝑎−(𝑏+ 𝑐−𝑑) = 𝑎−𝑏−𝑐+ 𝑑d<ć4ǦdíĚd/%
Ćć
Ds
[ 7-1ÊČ𝑥= 1
1
3d𝑦= −
1
2d𝑧=
5
6dt𝑥−(−𝑦) + (−𝑧) =
Āā0
Ă¢£57 ât=>dìÃZ¼;¶Ñ½ĠĀās
ąĄĄ
Ì = 𝑥+ 𝑦−𝑧 d
𝑥= 1
1
3d𝑦= −
1
2d𝑧=
5
6xd
Ì = 𝑥+ 𝑦−𝑧=
4
3 +(−
1
2)−
5
6 = 0 d
ĆĀāe 0s
ĈĉěĊĜ)=>'(dĄď57 x% ćƎs
[ 7-2ÊČ𝑥−( ) = 𝑥−𝑦−𝑧dt7 Ç_.ÿÿ1
As𝑦−𝑧
Bs𝑧−𝑦
Cs𝑦+ 𝑧
Ds−𝑦−𝑧
ĀāC
ĂěĊĜ67 âtdĄĀăďƶƅƷĢ67 ât
67 íxdǧ7Ġ7
Çå4 ¡~[d67 îxdǧ7Ġ7 Çå4 ¡Î[s
教辅资源,关注公众号★全科AA+
¢£67 âtĄĀ¶Ñd% [=s
ąĄĄ
¢£%¦𝑥−𝑦−𝑧67 d𝑥−𝑦−𝑧= 𝑥−(𝑦+ 𝑧)d
Ćć
Cs
[ 7-3ÊČ𝑥2 +2𝑥𝑦= 4d𝑦2 +𝑥𝑦= 5dt2𝑥2 +3𝑥𝑦−𝑦2 =
s
Āā3
Ă2𝑥2 +3𝑥𝑦−𝑦2=e2(𝑥2 + 2𝑥𝑦)−(𝑦2 + 𝑥𝑦)dì)Ã'(¶Ñs
ąĄĄ
∵𝑥2 +2𝑥𝑦= 4d𝑦2 +𝑥𝑦= 5d
∴2𝑥2 +3𝑥𝑦−𝑦2
= 2(𝑥2 + 2𝑥𝑦)−(𝑦2 + 𝑥𝑦)
= 2 × 4−5
= 3s
ĆĀāe
3s
ĈĉěĊĜ'Ą(dƷĢ“)Ãâ'Ą(”Ąěďs
【题型8 整式加减运算与化简求值】
8.24-25 ĐđĒē·ēƒ·ĖE1fgǨ
ēqvưÄĝařÙ¾ÄėqǩǪģ2Øôd
D 1 Ed¶5 + 6 = 11dů𝑎,𝑏ǫǬ|𝑎−3| + (𝑏+ 1)2 = 0dtD 2 E y (e
s
Āā27
ĂěĊĜn)89<=>'(õT^+𝑎d𝑏X`𝑚a𝑛dìX`¬𝑦¶Ñs¢£U
V(a¸ƢƬqÚîǎ'¬𝑎a𝑏(¶ÑĄŚMs
ąĄóČd
𝑚= 𝑎𝑏2 + 𝑎2𝑏+ 𝑎𝑏2 = 𝑎2𝑏+ 2𝑎𝑏2
𝑛= 𝑎2𝑏+ 𝑎𝑏2−3(𝑎2𝑏−𝑎) = 𝑎2𝑏+ 𝑎𝑏2−3𝑎2𝑏+ 3𝑎= −2𝑎2𝑏+ 𝑎𝑏2 +3𝑎
×µ𝑦= 𝑚+ 𝑛= 𝑎2𝑏+ 2𝑎𝑏2−2𝑎2𝑏+ 𝑎𝑏2 +3𝑎= −𝑎2𝑏+ 3𝑎𝑏2 +3𝑎s
教辅资源,关注公众号★全科AA+
Õe|𝑎−3| + (𝑏+ 1)2 = 0d
×µ𝑎−3 = 0d𝑏+ 1 = 0d
t𝑎= 3d𝑏= −1d
×µ𝑦= −32 × (−1) +3 × 3 × (−1)2 +3 × 3 = 27s
ĆĀāe
27s
[ 8-1.24-25 ĐđĒē·ƓƔǭǮ·ƃƄƅj1¼;s
(1)2(𝑥2−2𝑥𝑦)−3(𝑦2−3𝑥𝑦)
(2)(−𝑥2 + 2𝑥𝑦−𝑦2)−2(𝑥𝑦−3𝑥2) +3(2𝑦2−𝑥𝑦)s
Āā(1)2𝑥2−3𝑦2 +5𝑥𝑦
(2)5𝑥2−3𝑥𝑦+ 5𝑦2
ĂěġĊĜn)89díĚ/0234Ąďs
.11ƥ57 øƧ/0234½¬Āā
.21ƥ57 øƧ/0234½¬Āās
ąĄ.11Ą
2(𝑥2−2𝑥𝑦)−3(𝑦2−3𝑥𝑦)
= 2𝑥2−4𝑥𝑦−3𝑦2 + 9𝑥𝑦
= 2𝑥2−3𝑦2 +5𝑥𝑦
.21Ą
(−𝑥2 + 2𝑥𝑦−𝑦2)−2(𝑥𝑦−3𝑥2) +3(2𝑦2−𝑥𝑦)
= −𝑥2 + 2𝑥𝑦−𝑦2−2𝑥𝑦+ 6𝑥2 + 6𝑦2−3𝑥𝑦
= 5x2−3xy + 5y2
[ 8-2.24-25 ĐđĒē·ǯĪǰ·ĖE1Ř𝑀= 𝑥2 +4𝑚𝑥−3d𝑁= 2𝑥2 +4𝑚𝑥−2dÀÁ M < N p
öc. 1
As𝑀> 𝑁
Bs𝑀= 𝑁
Cs𝑀< 𝑁
DsLâĚ
ĀāC
ĂěĊĜn)89d~řǎǐdƶƅƷĢ)89:;Ąďs{¿¼;𝑀−𝑁d
=>i¢£O àápöcs
ąĄĄ
𝑀−𝑁= (𝑥2 + 4𝑚𝑥−3)−(2𝑥2 + 4𝑚𝑥−2)
= 𝑥2 + 4𝑚𝑥−3−2𝑥2−4𝑚𝑥+ 2
= −𝑥2−1
∵𝑥2 ≥0d
教辅资源,关注公众号★全科AA+
∴−𝑥2−1 ≤−1 < 0d
∴𝑀−𝑁< 0d
¶𝑀< 𝑁d
ćDZ Cs
[ 8-3.24-25 ƛđĒē·Dzdzŀ{·ĖE1ÊČ3𝑥2−4𝑥𝑦+ 7𝑦2−2𝑚= −17d𝑥2 +5𝑥𝑦+ 6𝑦2−𝑚= 12d
t_𝑥2−14𝑥𝑦−5𝑦2(e. 1
As−41
Bs−
41
2
Cs−
7
2
Ds
7
2
ĀāA
ĂěġĊĜn)=>'(dõÆÏřÄźwµ 2dìTÆř95ÆÏřÄ
źwµ 2 iO¶Ñ½ĠĀās
ąĄĄ∵𝑥2 +5𝑥𝑦+ 6𝑦2−𝑚= 12d
∴2(𝑥2 + 5𝑥𝑦+ 6𝑦2−𝑚) = 24d¶2𝑥2 +10𝑥𝑦+ 12𝑦2−2𝑚= 24d
∴3𝑥2−4𝑥𝑦+ 7𝑦2−2𝑚−(2𝑥2 + 10𝑥𝑦+ 12𝑦2−2𝑚) = −17−24 = −41d
∴3𝑥2−4𝑥𝑦+ 7𝑦2−2𝑚−2𝑥2−10𝑥𝑦−12𝑦2 +2𝑚= −41d
∴𝑥2−14𝑥𝑦−5𝑦2 = −41d
Ćć
As
【拔尖篇】
【题型9 程序框图中求代数式的值】
9.24-25 ĐđĒē·ħĨħĪ·ĖE1ǴǵxĖdőg{¿Ƕ_ĹOqmúǷbdD 1 eƏ
Ǹv/ĹǹǹőǺǻǼǽðÖƉ&Ƕ_ēĹOdǫǾødúǷnËgŔĝë×Ĺǹǿ
bsů¾bȀøȁȂÃD 2 AB¼;dtÐiȂ¬O s
Āā21
ĂěĊĜ+Ďwq:;µ*'(dõ¢£D 1d½¬𝑥= 2 × 52 +0 + 1 = 51dìÃ
AB¼;d¶Ñ'Ąs
ąĄĄ
ð%d𝑥= 2 × 52 +0 + 1 = 51
教辅资源,关注公众号★全科AA+
∴51−10 = 41 > 30
41−10 = 31 > 30
31−10 = 21 < 30
Ȃ¬21
ĆĀāe
21s
[ 9-1.24-25 ȃđĒė·ūŬȄȅ·Ėł1DdÙ[b xdy AB¼;důȆȇȂà x (e 2d
tÐiȂ¬Õ[b y (e
As3
Bs8
Cs63
Ds64
ĀāC
ĂěĊĜº»ABȈAD<'(s¢£ABȈADdº»'dȆȇȂÃ𝑥(e 2 xd
Ã𝑦= (𝑥+ 1)(𝑥−1) = (2 + 1)(2−1) = 3 < 15dǺƧìȂÃ𝑥= 3dƥĠpÙ 15 ѽĀās
ąĄĄ
ó%ѽd𝑥= 2xd𝑦= (𝑥+ 1)(𝑥−1) = (2 + 1)(2−1) = 3 < 15d
𝑥= 3xd𝑦= (𝑥+ 1)(𝑥−1) = (3 + 1)(3−1) = 8 < 15d
𝑥= 8xd𝑦= (𝑥+ 1)(𝑥−1) = (8 + 1)(8−1) = 63 > 15d
∴Ȃ¬𝑦= 63d
Ćć
Cs
[ 9-2.24-25 ĐđĒē·ĽȉYĪ·Ėł1+(ȊÉȋdÌĎD×`důȆȇȂà x ( 5d
ÑȌĥÆ 1 ÖȂ¬O 16dÆ 2 ÖȂ¬O 8dÆ 3 ÖȂ¬O 4sðÖȍȎė5dÆ 2025
ÖȂ¬O. 1
As8
Bs4
Cs2
Ds5
ĀāB
ĂěĊĜn+Ďȏ/:;d¢£Ȑ×§:;ABdõ¼;¬FÖȂ¬Od½¬æ#
教辅资源,关注公众号★全科AA+
I
ǺÆ 3 ÖȆȇdȂ¬OÝ 3 Öº» 4d2d1 ÍBȑƜd¶ÑĄĀs
ąĄĄ
¢£%ѽ
Æ 1 ÖȂ¬O 16d
Æ 2 ÖȂ¬O 8d
Æ 3 ÖȂ¬O 4d
Æ 4 ÖȂ¬O
1
2 × 4 = 2d
Æ 5 ÖȂ¬O
1
2 × 2 = 1d
Æ 6 ÖȂ¬O3 × 1 + 1 = 4d
Æ 7 ÖȂ¬O 2d
Æ 8 ÖȂ¬O 1d
Æ 9 ÖȂ¬O 4d
……d
ǺÆ 3 ÖȆȇdȂ¬OÝ 3 Öº» 4d2d1 ÍBȑƜd
(2025−2) ÷ 3 = 674…1d
∴Æ 2025 ÖȂ¬OÆ 675 ÖȑƜEÆ 1 d
∴Æ 2025 ÖȂ¬Oe 4d
Ćć
Bs
[ 9-3.2025·ĽȉYĪ·ÏƗ1D:;AB`%DdůȆȇȂÃ𝑥(e 5dtȂ¬𝑦(e
s
Āā13
ĂěĊĜn'(dȒȓ:;ABDĄďs¢£5 > 4a:;ABDd¦𝑥= 5Ã
𝑦= 2𝑥+ 3¼;¶Ñ½s
ąĄĄ
∵5 > 4d
∴ůȆȇȂÃ𝑥(e 5dtȂ¬𝑦(e2 × 5 + 3 = 13d
ĆĀāe
13s
教辅资源,关注公众号★全科AA+
【题型10 几何图形中求代数式的值】
10.24-25 ĐđĒē·ǯĪǰ·ĖE1ė&Ľ)Ed~ÒX`DEȔƿŊÔ. 1
As𝑎𝑏−(𝑎−2)(𝑏−3)
Bs2𝑏+ 3(𝑎−2)
Cs2(𝑏−3) + 3(𝑎−2) + 6
Ds3𝑎+ 2(𝑏−2)
ĀāD
ĂěĊĜníqHaŸqHÔ ČčĄďƶƅƷĢǎǐdǺƧ¸
'Ąs
O/%d¢£íqHaŸqHÔ ǎǐ¼;d¶Ñ½ĠĀās
ąĄĄ
Dd
ȔƿŊÔѵƪŸ𝑎dŹe𝑏ŸqHÔ95Ÿ𝑎−2dŹe𝑏−3ŸqHÔd¶𝑎𝑏−(𝑎−2)
(𝑏−3)dĆ A ć4íĚd~/%
ȔƿŊÔѵƪŸ 2dŹe𝑏−3ŸqHÔ8ēŸ 3dŹe 2 ŸqHÔ8ēŸ𝑎−2d
Źe 3 ŸqHÔd¶2(𝑏−3) + 3(𝑎−2) + 6dĆ C ć4íĚd~/%
ȔƿŊÔѵƪŸ𝑏dŹe 2 ŸqHÔ8ēŸ𝑎−2dŹe 3 ŸqHÔd¶
2𝑏+ 3(𝑎−2)dĆ B ć4íĚd~/%
ȔƿŊÔѵƪŸ 2dŹe𝑏−3ŸqHÔ8ēŸ𝑎dŹe 3 ŸqHÔd¶
3𝑎+ 2(𝑏−3)dĆ D ć4ũŪd/%
Ćć
D
[ 10-1.24-25 ĐđĒē·śŜǑǒ·Ėł1D×`ŸqHs
教辅资源,关注公众号★全科AA+
.11¢£DEȕȖpödT^ x X`ȔƿŊÔ𝑆=
.21ů𝑥= 4d' S (
s
Āā
18 + 3𝑥
30
ĂěĊĜnX`d'(s
.11¢£DHÔȗâd&¬X`ȔƿÔ¶Ñs
.21¢£Z\(d'(¶Ñs
ąĄ.11Ą
𝑆=
1
2 × 6 × 12−
1
2 × (12−6)(6−𝑥) = 18 + 3𝑥d
ĆĀāe
18 + 3𝑥
.21Ą
𝑥= 4xd𝑆= 18 + 3 × 4 = 30d
ĆĀāe
30s
[ 10-2.24-25 ĐđĒē·Ƣƞ·Ėł1Dd7¸Ƣv2öŸqHȘșȚpŸqHdůöŸ
qHŹe𝑎dtpŸqHNjŸ
s
Āā
38
3 𝑎
ĂěĊĜ&d)89:;STd¢£öŸqHŹe𝑎dtöŸqHŸe
4
3𝑎dO/
pŸqHȚǜqdÑT^𝑎X`¬pŸqHŸ<Źd¶Ñ½¬OPs¢£åbĝĞcd
T^𝑎X`¬pŸqHŸ<ŹĄďs
ąĄĄ
∵öŸqHŹe𝑎dtöŸqHŸe
4
3𝑎d
∴pŸqHŸe4𝑎dpŸqHŹe
4
3𝑎+ 𝑎=
7
3𝑎d
∴2 4𝑎+
7
3 𝑎= 2 ×
19
3 𝑎=
38
3 𝑎d
∴pŸqHNjŸ
38
3 𝑎s
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ĆĀāe
38
3 𝑎s
[ 10-3.24-25 ĐđĒė·śŀțĪ·ĖE1D L HȜȝȞd5 2ļ&¬ÜȞÔ
;dŇȟeíĚ+. 1
①𝑎𝑐−(𝑏−𝑐)𝑐②(𝑎−𝑐)𝑐+ 𝑏𝑐③(𝑎−𝑐)𝑐+ 𝑐2 + (𝑏−𝑐)𝑐④𝑎𝑏+ 𝑏𝑐−𝑐2⑤𝑎𝑏−(𝑎−𝑐)(𝑏−𝑐)
As①②③
Bs②③⑤
Cs③④⑤
Ds①②③④⑤
ĀāB
ĂěġĊĜn&dĄĂDEǾƝȠȡdļ&'¬ L ԶѽĠĀās
ąĄĄ
①Dd
𝐿Ô = ǽźȢȣŸqHÔ + ėȤȣŸqHÔ = 𝑎𝑐+ (𝑏−𝑐)𝑐dĆ①ũŪ
②Dd
𝐿Ô = ēźȢȣŸqHÔ + ėȤȣŸqHÔ = (𝑎−𝑐)𝑐+ 𝑏𝑐dĆ②íĚ
③Dd
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𝐿Ô = ÄŸqHÔ + öíqHÔ = (𝑎−𝑐)𝑐+ (𝑏−𝑐)𝑐+ 𝑐2d Ć③íĚ
④Dd
𝐿Ô = ȢȣŸqHÔ + ȤȣŸqHÔ−ƱƲŊíqHÔ = 𝑎𝑐+ 𝑏𝑐−𝑐2dĆ④ũ
Ū
⑤Dd
𝐿Ô = ŸqHÔ−óȥȦȧȨöŸqHÔ = 𝑎𝑏−(𝑎−𝑐)(𝑏−𝑐)dĆ⑤íĚd
ľēѽ
②③⑤íĚd
Ćć
Bs
【题型11 数式规律探究】
11.24-25 ĐđĒē·ǯĪ·Ėł1ė&DāƐpǀȩųŊd³E“○”XȩȪē×ȫȬȪd
tÆ n DE×ȫȬȪ“○”e. 1s
As2𝑛+ 1
Bs2𝑛+ 2
Cs3𝑛+ 1
Ds3𝑛+ 2
ĀāD
ĂěġĊĜnDH3#IdŃĚ%dǙĚ½Ġ#IĄďsȭȮDHÑČÆD
āe3 + 2 = 5ȩŦÆÏDāe2 × 3 + 2 = 8ȩŦÆûDāe3 × 3 + 2 = 11ȩŦ……óă½
Ġ
Æ n Dā×ȫȩŦd¶Ñ'Ąs
ąĄĄ
ÆDāe3 + 2 = 5ȩŦ
ÆÏDāe2 × 3 + 2 = 8ȩŦ
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ÆûDāe3 × 3 + 2 = 11ȩŦ
……
óă½Ġ
Æ n Dā×ȫȩŦe3𝑛+ 2s
Ćć
Ds
[ 11-1.24-25 ĐđĒė·ĿŀȯƖ·ȆĊȰ1fƞŀȱŞȲȳȌĥnD×`ûȴHXd
fgÈĝe“Ȳȳûȴ”sDEÄȧĝĞ&
1d3d6d10d15d…dfgÆúe𝑎1dÆÏ
úe𝑎2dÆûúe𝑎3d…dÆ𝑛úe𝑎𝑛dt𝑎9−𝑎6 + 𝑎5(. 1
As17
Bs27
Cs39
Ds45
ĀāC
ĂěĊĜn#I
Z[=3d'(sĄŚěď¢£Z[=ȵǛ#
Is¢£%½¬Æ𝑛úe𝑎𝑛= 1 + 2 + 3 + …… + 𝑛=
1
2𝑛(𝑛+ 1)dìÃ'(døƧѽOs
ąĄĄ
Æúe𝑎1 = 1d
ÆÏúe𝑎2 = 1 + 2 = 3d
Æûúe𝑎3 = 1 + 2 + 3 = 6d
…d
Æ𝑛úe𝑎𝑛= 1 + 2 + 3 + …… + 𝑛=
1
2𝑛(𝑛+ 1)d
Ć𝑎9 =
1
2 × 9 × 10 = 45d𝑎6 =
1
2 × 6 × 7 = 21d𝑎5 =
1
2 × 5 × 6 = 15d
𝑎9−𝑎6 + 𝑎5 = 45−21 + 15 = 39s
Ćć
Cs
[ 11-2.24-25 ĐđĒē·śŀțĪ·Ėł1ȶÞȷȸȹÙśƔȺȻƔŊȼǪ——ȽȾdfƞǵ
ȿŃɀɁɂɃǭɄdȶÞȷɅɆɇɈ 4.5 ɉNƬqžd°+ɊHɋɌaɂɃɍɎsDdeȶÞȷ
ɇɈɏƣdöŃȌĥdɇɈɏƣEɐɑɒȣČčd³EÆ①DāE+ 5 ŦɓDādÆ 2 DāE
+ 8 ŦɓDādÆ③DāE+ 11 ŦɓDād……dºă#IƉ&ė5dtÆ 100 DāEŦɓDā
e. 1
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As302
Bs301
Cs303
Ds300
ĀāA
ĂěĊĜnDH[=#Id¢£DH[=½¬Æ𝑛DHE+(3𝑛+ 2)ŦɓDāĄ
ďs
¢£DH[=#I½¬Æ𝑛DHE+(3𝑛+ 2)ŦɓDā¶ÑĄĀs
ąĄóČdÆ①DāE+2 × 2 + 1 = 5ŦɓDādÆ②DāE+2 × 3 + 2 = 8ŦɓDād
Æ③DāE+2 × 4 + 3 = 11ŦɓDād…dÆ𝑛DāE+2(𝑛+ 1) +𝑛= 3𝑛+ 2ŦɓDād
𝑛= 100xd3𝑛+ 2 = 3 × 100 + 2 = 302d
ĆÆ 100 DāEŦɓDāe 302s
Ćć
As
[ 11-3.24-25 ɔđĒė·Ʊɕɖŀ·Ėł1ɗƝ+ɘ=/ǿdѵ/c&ə¤ǿsDT
öɚɛƭƮɗ*³ə¤ǿOȨdÆ①DHé 9 ¢öɚɛdÆ②DHé 16 ¢dÆ③DH
é 23 ¢d……dºă#IdÆ⑩DHéöɚɛ¢. 1
As85
Bs81
Cs76
Ds72
ĀāD
ĂěĊĜnDH#IdĎĄbcdǛ¬#Iďs
¢£%½ĠÆ n DHé9 + 7(𝑛−1) = 7𝑛+ 2.¢1dóă¶Ñ'Ąs
ąĄĄ
Æ①DHé 9 ¢öɚɛd
Æ②DHé 16 ¢d¶16 = 9 + 7d
Æ③DHé 23 ¢d¶23 = 9 + 2 × 7d
∴Æ n DHé9 + 7(𝑛−1) = 7𝑛+ 2.¢1d
Æ⑩DHé7 × 10 + 2 = 72.¢1d
Ćć
Ds
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【题型12 整式加减中的无关项问题】
12.24-25 ĐđĒē·Dzdzŀ{·ĖE1Ù𝑥d𝑦N4𝑥2 +𝑎𝑥−𝑦+ 𝑏<N4𝑏𝑥2−3𝑥+ 6𝑦−3
(<Z\𝑥Ǝ(Ldt3(𝑎2−2𝑎𝑏−7)−(4𝑎2 + 𝑎𝑏+ 𝑏2)(e
s
Āā−10
ĂăĊĜn)89-=>'(dƶƅƷĢ:;âtĄěďs¢£%&¬cdó
O< x (Ld̬ a < b (dÌ57 /0iü;¶Ñ'¬(s
ąĄĄ
𝑥2 +𝑎𝑥−𝑦+ 𝑏−(𝑏𝑥2−3𝑥+ 6𝑦−3) = (1−𝑏)𝑥2 +(𝑎+ 3)𝑥−7𝑦+ 3 + 𝑏
∵N4𝑥2 +𝑎𝑥−𝑦+ 𝑏<N4𝑏𝑥2−3𝑥+ 6𝑦−3(<Z\ x Ǝ(Ld
∴ 1−𝑏= 0 d𝑎+ 3 = 0d
∴ 𝑏= 1,𝑎= −3d
∵ 3(𝑎2−2𝑎𝑏−7)−(4𝑎2 + 𝑎𝑏+ 𝑏2)
= 3𝑎2−6𝑎𝑏−21−4𝑎2−𝑎𝑏−𝑏2
= −𝑎2−7𝑎𝑏−𝑏2−21
𝑏= 1,𝑎= −3x
Ì = −9 + 21−1−21 = −10d
ĆĀāe
−10s
[ 12-1.24-25 ĐđĒē·Ĕĕ·ĖE1ůÙ x y N4 8(𝑥2−3𝑥𝑦−𝑦2)−2(𝑥2 + 𝑚𝑥𝑦+ 2𝑦2)=>
i~^𝑥𝑦4dt𝑚=
s
Āā−12
ĂěĊĜn)89ELMd¢£=>i~^𝑥𝑦4d¶𝑥𝑦ce 0døƧÑ'Ąs
ąĄĄ
8(𝑥2−3𝑥𝑦−𝑦2)−2(𝑥2 + 𝑚𝑥𝑦+ 2𝑦2)
= 8𝑥2−24𝑥𝑦−8𝑦2−2𝑥2−2𝑚𝑥𝑦−4𝑦2
= 6𝑥2−12𝑦2−(24 + 2𝑚)𝑥𝑦d
∵=>i~^𝑥𝑦4d
∴24 + 2𝑚= 0d
Ą½
𝑚= −12d
ĆĀāe
−12s
[ 12-2.24-25 ĐđĒē·ūŬɜ»·Ėł1ÊČ^Z\𝑚d𝑛
3 𝑚2 + 2(𝑛2 + 𝑚𝑛−3) −3
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(𝑚2 + 2𝑛2)−4(𝑚𝑛−𝑚−1)s
(1)=>¾s
(2)öŃƎ 𝑚d𝑛 ǸeɝV(Ã=>Edɞș¼;½(řÙ 0sÀÁöŃ×Ǝ
Z\ 𝑛 (řÙNŖŗ
(3)ɟŃöɠǺ=>EȌĥdŨZ\ 𝑛 ƎɡdLPZ\ 𝑚 ƎGd(ɢ
e~[dÀÁöɠ×ƎZ\ 𝑛 (NŖɣŗ
Āā(1)2𝑚𝑛+ 4𝑚−14
(2)𝑛=
1
3
(3)𝑛= −2
ĂěĊĜ)89ELMdíĚ¼;ď
.1157 d/0234d=>¶Ñ
.21¢£ǸeɝÄĝÔe1d½Ġ𝑚𝑛= 1dÃ=>id'¬𝑚(døƧ'¬𝑛(¶Ñ
.31¢£%d½Ġ(<Z\𝑚Ld½Ġ𝑚ce 0døù'Ą¶Ñs
ąĄ.11Ą
Ì = 3𝑚2 +(6𝑛2 + 6𝑚𝑛−18) −(3𝑚2 + 6𝑛2)−(4𝑚𝑛−4𝑚−4)
= 3𝑚2 + 6𝑛2 + 6𝑚𝑛−18−3𝑚2−6𝑛2−4𝑚𝑛+ 4𝑚+ 4
= 2𝑚𝑛+ 4𝑚−14
.21Ą
ó%d½
𝑚𝑛= 1dÃ2𝑚𝑛+ 4𝑚−14d½
2 × 1 + 4𝑚−14 = 0d
Ą½
𝑚= 3d
∴𝑛=
1
3
.31Ą
∵2𝑚𝑛+ 4𝑚−14 = (2𝑛+ 4)𝑚−14d
∴2𝑛+ 4 = 0d¶
𝑛= −2xd2𝑚𝑛+ 4𝑚−14 = (2𝑛+ 4)𝑚−14 = −14e(
Ć𝑛= −2s
[ 12-3.24-25 ĐđĒē·njŬɤ·ƃƄƅj1ɥȒ<ljĊ:ɥȒė&ȝɦd¸iɧɨs
ŔdfƐɩɪēƪĠ¾ƣŅ
öɫaöɬ¸Ȑ“=>𝑇(𝑥−1) + 3(𝑥−4) + 5”xdȌĥc“𝑇”
ǧɭɮɯɰndėɱɲVɳ
öɫ
öɬdfNJdǧɭɮɯɰc𝑇−4
öɬ
Ňɴũɵ!fĜnėd¾ŅĀā|ɶɷ......
ɧɨ
教辅资源,关注公众号★全科AA+
(1)¢£ȝɦEöɫɳd=>_𝑇(𝑥−1) + 3(𝑥−4) + 5s
(2)¢£ȝɦEöɬɳd'¾ŅMEc“𝑇”*Ļ_Os
Āā(1)−𝑥−3
(2)c“𝑇”e−3Ļ_Oe−4
ĂěġĊĜ)89dƶƅƷĢ/0234Ąď
.11õ57 dì/0234døƧ½¬Āā
.21õ57 dì/0234dìLjTO|d½¬Āās
ąĄ.11∵c−4d
∴−4(𝑥−1) + 3(𝑥−4) + 5
= −4𝑥+ 4 + 3𝑥−12 + 5
= −𝑥−3s
.21Ì = 𝑇(𝑥−1) +3(𝑥−4) +5
= 𝑇(𝑥−1) + 3𝑥−7
= (𝑇+ 3)𝑥−𝑇−7d
∵¼;O|d
∴𝑇+ 3 = 0d
∴ 𝑇= −3.
∴−3(𝑥−1) +3(𝑥−4) +5 = −3𝑥+ 3 + 3𝑥−12 + 5 = −4s
【题型13 整式加减中的多结论问题】
13.24-25 ĐđĒē·ɸDzɹɺ·Ėł1DdpŸqHEƮÃnĶ e①d②d③d④d⑤
ǾĽźHd³E①d②eÄŸqHd③d④d⑤eûíqHdvưDHĝĞǸ~ƱƲLɻ
ɼsůNJ'½ŸqH②NjŸdō Ŏ ɽ ɾĽ2Ĵ¬nɿʀNJâ
ōĸ
ŨéČŅ①<③NjŸa
Ŏĸ
ŨéČŅ①<⑤NjŸa
ɽĸ
ŨéČŅ③<④NjŸa
ɾĸ
ŨéČŅ⑤<①NjŸ
ė&ĸâíĚ. 1
教辅资源,关注公众号★全科AA+
AsŨ+ōíĚ
BsōaŎƴíĚ
CsŎaɽƴíĚ
DsŨ+ɾíĚ
ĀāA
ĂěġĊĜn)89STdíqHaʁHǎǐdĄď{¿Ř③źŸe𝑎d④
źŸe𝑏d②Źe𝑥d'¬åDHNjŸs
Ř③źŸe𝑎d④źŸe𝑏d②Źe𝑥d¢£DH'¬⑤źŸe𝑎+ 𝑏d②Ÿe
𝑎+ 𝑎+ 𝑏= 2𝑎+ 𝑏d①Ÿe𝑥+ 𝑎dŹe𝑏−𝑎d÷iõ'¬②NjŸdìļ;¬①③④⑤NjŸd
Ði{¿¼;①<③NjŸa ①<⑤NjŸa ③<④NjŸa ⑤<①NjŸd<②NjŸ
ŕʂdìøùàá¶Ñs
ąĄĄ
Ř③źŸe𝑎d④źŸe𝑏d②Źe𝑥d
∴⑤źŸe𝑎+ 𝑏d②Ÿe
𝑎+ 𝑎+ 𝑏= 2𝑎+ 𝑏d①Ÿe𝑥+ 𝑎dŹe𝑏−𝑎d
∴②NjŸe
2(2𝑎+ 𝑏+ 𝑥) = 4𝑎+ 2𝑏+ 2𝑥d
∵①NjŸ = 2(𝑥+ 𝑎+ 𝑏−𝑎) = 2𝑥+ 2𝑏d③NjŸe4𝑎d
∴①<③NjŸae
4𝑎+ 2𝑏+ 2𝑥d
∴ōĸâíĚ
∵①NjŸ = 2(𝑥+ 𝑎+ 𝑏−𝑎) = 2𝑥+ 2𝑏d⑤NjŸe4(𝑎+ 𝑏) = 4𝑎+ 4𝑏d
∴①<⑤NjŸae
4𝑎+ 4𝑏+ 2𝑥+ 2𝑏= 4𝑎+ 6𝑏+ 2𝑥d
∴ŎĸâũŪ
∵③NjŸ = 4𝑎d④NjŸ = 4𝑏d
∴③<④NjŸae
4𝑎+ 4𝑏d
∴ɽĸâũŪ
∵⑤NjŸe4(𝑎+ 𝑏) = 4𝑎+ 4𝑏d①NjŸ = 2(𝑥+ 𝑎+ 𝑏−𝑎) = 2𝑥+ 2𝑏d
∴⑤<①NjŸe
4𝑎+ 4𝑏−2𝑥−2𝑏= 4𝑎+ 2𝑏−2𝑥d
∴ɾĸâũŪ
ľēÑČ
ĸâíĚŨ+ōd
Ćć
As
[ 13-1.24-25 ȃđĒē·ūŬʃʄ·Ėł1Ù xdy 4dů x Ø< y Øvří)
教辅资源,关注公众号★全科AA+
dtÈĻ4“řÖ4”s§¬ėĽOP
①−5𝑥3𝑦3“řÖ4”②“řÖ4”Ö
ÑÒʅ③ÄÖvř“řÖ4”a“řÖ4”④ůǾ“řÖ4”Ö
ƴ~ÞÙ 8dtÜgEã+234sē«OPEd×+íĚOPB . 1
As①②③
Bs①④
Cs①②④
Ds①③④
ĀāB
ĂěĊĜ234d/0234d4Öd¢£ʆdO/234µ*/0234âtd
ğøùàá¶Ñs
ąĄĄ
−5𝑥3𝑦3E x Ø< y Øvří)d“řÖ4”Ć①íĚ
“řÖ4”Öãeʇd~ÑÒʅĆ②ũŪ
ÄÖvř“řÖ4”a~“řÖ4”dÑÒe 0dĆ③ũŪ
ůǾ“řÖ4”Öƴ~ÞÙ 8dt𝑥dy Ðpe 4dtÜgEã+234sĆ④íĚ
Ćć Bs
[ 13-2+ðÖƉ&Ä)
𝑥,𝑥+ 3dVɧ%vưÄ)d¡Tǻź)9ǽź)d
¦×½ĝ"¾Ä)ĝĞdѵ½Ġʆ)ʈ
𝑥,3,𝑥+ 3d¾ÈeÆÖʉ¦ÆÖʉ
i)ʈºē«qìýÖʉdѵ½ĠÆÏÖʉi)ʈµă3ʊs{¿ė&QRʉd
①ÆÏÖʉi)ʈe
𝑥,3−𝑥,3,𝑥,𝑥+ 3
②ÆÏÖʉid𝑥ʋ−3]𝑥ʌ3xd×+)Ôeí
③ÆĽÖʉi)ʈģ+ 19 )
④Æ 2022 Öʉid×+)ĝae2𝑥+ 6069ē«OPEdíĚ.ÿÿ1
As①②
Bs①③
Cs①④
Ds②④
ĀāC
Ă¢£:;ʆȨʍ)ǜdº»'¼; ȵǛ#Iàá¶Ñs
ąĄ∵ÆÖʉi)ʈe
𝑥,3,𝑥+ 3d
∴ÆÏÖʉi)ʈe𝑥,3−𝑥,3,𝑥+ 3−3,𝑥+ 3d
¶𝑥,3−𝑥,3,𝑥,𝑥+ 3d
Ć①OPíĚd/%
ÆÏÖʉi)Ôe𝑥× (3−𝑥) × 3 × 𝑥× (𝑥+ 3) = 3𝑥2(9−𝑥2)d
∵𝑥ʋ−3]𝑥ʌ3d
∴𝑥2ʌ9d
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¶9−𝑥2ʋ0d
∴3𝑥2(9−𝑥2)ʋ0d
¶ÆÏÖʉid𝑥ʋ−3]𝑥ʌ3xd×+)Ôeîd
Ć②ĸâũŪd~/%
ÆûÖʉi)ʈe𝑥,3−2𝑥,3−𝑥,𝑥,3,𝑥−3,𝑥,3,𝑥+ 3d
ÆĽÖʉi)ʈe𝑥,3−3𝑥,3−2𝑥,𝑥,3−𝑥,2𝑥−3,𝑥,3−𝑥,3,𝑥−6,𝑥−3,3,𝑥,3−𝑥,3,𝑥,𝑥+ 3d
ģ 17 d
Ć③ĸâũŪd~/%
ÆÖʉi×+)ae𝑥+ 3 + 𝑥+ 3 = 2𝑥+ 6 = 2𝑥+ 3 × (1 + 1)d
ÆÏÖʉi×+)ae𝑥+ 3−𝑥+ 3 + 𝑥+ 𝑥+ 3 = 2𝑥+ 9 = 2𝑥+ 3 × (2 + 1)d
ÆûÖʉi×+)ae
𝑥+ 3−2𝑥+ 3−𝑥+ 𝑥+ 3 + 𝑥−3 + 𝑥+ 3 + 𝑥+ 3 = 2𝑥+ 12 = 2𝑥+ 3 × (3 + 1)d
...d
Æ n Öʉi×+)ae2𝑥+ 3 × (𝑛+ 1)d
∴Æ 2022 Öʉid×+)ae2𝑥+ 3 × (2022 + 1) = 2𝑥+ 6069d
Ć④ĸâíĚd/%
íĚĸâ+①④d
Ćć
Cs
ĈĉěĊĜn)89E#IɴNJd)89dƶƅƷĢ#IȵǛǠěqôdíĚøù)
89Ąďs
[ 13-3.24-25 ĐđĒė·ūŬʎʏ·Ėł1+ðÖƉ& 2 )
𝑥+ 𝑦d𝑥−𝑦s
¦Æ 1 )wµ 2 ì<Æ 2 )v8d½ĠÆ 3 )3𝑥+ 𝑦dÈeÆÖʉ
¦Æ 2 )wµ 2 ì<Æ 3 )v8d½ĠÆ 4 )5𝑥−𝑦dÈeÆÏÖʉ
¦Æ 3 )wµ 2 ì<Æ 4 )v8d½ĠÆ 5 )11𝑥+ 𝑦dÈeÆûÖʉd……d
µă3ʊdė&ĸâ
①ÆȃÖʉ½Ġ)e85𝑥−𝑦
②Æ 20 )E^𝑥4c 2 Š<Æ 21 )E^𝑥4cĝe 1
③Æ 2025 )aÆ 2026 )E^𝑥4cĝařÙ22025s
³EíĚ+ s
教辅资源,关注公众号★全科AA+
Āā①③
ĂěġĊĜn)89¼;d<N4+#IJWd¢£%ļ'¬ 8 )O
dѽ#I n eʅxdÆ n )E^ x 4c 2 ŠŕÆ(𝑛+ 1))E^ x 4cp 1d
n eʇxdÆ n )E^ x 4c 2 ŠŕÆ(𝑛+ 1))E^ x 4cö 1dÆ n )E
^ x 4c<Æ(𝑛+ 1))E^ x 4cĝae2𝑛d£ăàá'Ą¶Ñs
ąĄĄ
Æ 1 )e𝑥+ 𝑦d
Æ 2 )e𝑥−𝑦d
Æ 3 )e3𝑥+ 𝑦d
Æ 4 )e5𝑥−𝑦d
Æ 5 )e2(3𝑥+ 𝑦) +5𝑥−𝑦= 6𝑥+ 2𝑦+ 5𝑥−𝑦= 11𝑥+ 𝑦d
Æ 6 )e2(5𝑥−𝑦) +11𝑥+ 𝑦= 10𝑥−2𝑦+ 11𝑥+ 𝑦= 21𝑥−𝑦d
Æ 7 )e2(11𝑥+ 𝑦) +21𝑥−𝑦= 22𝑥+ 2𝑦+ 21𝑥−𝑦= 43𝑥+ 𝑦d
Æ 8 )e2(21𝑥−𝑦) +43𝑥+ 𝑦= 42𝑥−2𝑦+ 43𝑥+ 𝑦= 85𝑥−𝑦dĆ①íĚ
……d
µă3ʊÑČd n eʅxdÆ n )E^ x 4c 2 ŠŕÆ(𝑛+ 1))E^ x 4cp 1d
n eʇxdÆ n )E^ x 4c 2 ŠŕÆ(𝑛+ 1))E^ x 4cö 1dÆ n )E
^ x 4c<Æ(𝑛+ 1))E^ x 4cĝae2𝑛d
∴Æ 20 )E^𝑥4c 2 Š<Æ 21 )E^𝑥4cĝe−1dÆ 2025 )aÆ 2026
)E^𝑥4cĝařÙ22025dĆ②ũŪd③íĚ
ĆĀāe
①③s
【题型14 整式加减的实际应用】
14.24-25 ĐđĒē·Dzdzŀ{·ƃƄƅj1fʐƐöʑʒƠǂTɿmƫ 2024 đĶǙʓŧė.ƫŧº
ʔʓLJ1
TʕʔTƫb
ĵ
~ʖ¿ 12 ʗqžŊ
𝑎ij/ʗqž
ʖ¿ 12 ʗqžü~ʖ¿ 20 ʗqžŊ
1.5𝑎ij/ʗqž
ʖ¿ 20 ʗqžŊ
2𝑎ij/ʗqž
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(1)Ɛʕ 4 ʔʘTn 15 ʗqžƫd'Ļʕ 4 ʔʘSʓLJƫŧ.T^𝑎_X`1
(2)ŘƐʕʔTƫbe𝑛ʗqžd𝑎= 2.5xdůĻTʕʓLJƫŧ 110 ijdtĻTʕ¾ʔTƫbNŖʗ
qž.&qA'Ą1ŗ
(3)𝑎= 2xdō ŎÄʕʔģTƫ 32 ʗqždÊČōʕʓLJƫŧʖ¿n 24 ijdŘōʕ¾ʔTƫ
𝑥ʗqždȰ'ōdŎÄʕʔģʓLJƫŧ.ÑT^𝑥_X`1
Āā(1)16.5𝑎ij
(2)30 ʗqž
(3)12 < 𝑥≤20xdōŎģʓLJ 72 ij20 < 𝑥≤32xdōŎģʓLJ(2𝑥+ 32)ij
ĂěĊĜn)89STdijÖqA¤¥QRSTdíĚĎĄƄƇĈĄďs
.11¢£ʓŧĶǙĄĀ¶Ñ'Ą
.21ŘĻTʕ¾ʔTƫb m ʗqžd¢£%ѽ𝑚> 20d÷i&¬qAd¶Ñ'Ą
.31ÄƝȠȡ
12 < 𝑥≤20xd20 < 𝑥≤32xd¢£%d&¬d¶Ñ'Ąs
ąĄ.11Ą
12𝑎+ (15−12) × 1.5𝑎= 16.5𝑎ijd
¶Ļʕ 4 ʔʘSʓLJƫŧe16.5𝑎ij
.21Ą
ŘĻTʕ¾ʔTƫb m ʗqžd
∵2.5 × 12 = 30 < 110d30 + (20−12) × 1.5 × 2.5 = 60 < 110d
∴𝑚> 20d
¢£%½
60 + 2 × 2.5(𝑚−20) = 110d
Ą½
𝑚= 30d
Ā
ĻTʕ¾ʔTƫb 30 ʗqž
.31Ą
𝑎= 2xd12 × 2 = 24ijd
¢£%d½ōʕʓLJƫŧʖ¿n 24 ijd
Řōʕ¾ʔTƫ𝑥ʗqždt𝑥> 12d
12 < 𝑥≤20xdōʕTƫbʖ¿12m3ü~ʖ¿20m3dŎʕTƫb~ŖÙ12m3üŖÙ20m3d
×µō ŎÄTʕʔģʓLJƫŧe
[12 × 2 + (𝑥−12) × 1.5 × 2] + [12 × 2 + (32−𝑥−12) × 1.5 × 2]
= (24 + 3𝑥−36) + (24 + 60−3𝑥)
= 72ij
20 < 𝑥≤32xdōTƫbʖ¿20m3dŎTƫb~ʖ¿12m3d
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×µō ŎÄTʕʔģʓLJƫŧe
[12 × 2 + (20−12) × 1.5 × 2 + (𝑥−20) × 2 × 2] + (32−𝑥) × 2
= (24 + 24 + 4𝑥−80) + (64−2𝑥)
= (2𝑥+ 32)ijd
ľē׫d12 < 𝑥≤20xdōŎģʓLJ 72 ij20 < 𝑥≤32xdōŎģʓLJ(2𝑥+ 32)ijs
[ 14-1.25-26 ĐđĒē·Ƣƞ·ʙʚƅj1ƐèʒƠ¤¥TƫʛŧĶǙe
ÝʔTƫb~ʖ¿15
m3dÝʗqž a ijʖ¿ŊÝʗqž(𝑎+ 2)ijsůĻèʑƐŞʜēʔTƫbe20m3dtSʓƫŧNŖijŗ
ĀāSʓƫŧ(20𝑎+ 10)ij
ĂěĊĜ)89QRSTd¢£ʛŧĶǙd&¬døù¼;¶Ñs
ąĄĄ
15𝑎+ (20−15)(𝑎+ 2) = 15𝑎+ 5𝑎+ 10 = 20𝑎+ 10.ij1d
Ā
Sʓƫŧ(20𝑎+ 10)ijs
[ 14-2.24-25 ĐđĒē·njŬɤ·ƃƄƅj14Ȑjs
ġȬȪs
ʝȝʞźŸe𝑎íqHȪʟ Ȭʠřs
ʉǺźŸe𝑎íqHȪʟ.D 11ēȬ5Äv2öŸqHd½ĠɋɃZ“5”Dā
.D 21dì¦ȬėÄöŸqHȚʆŸqH.D 31s
JK
(1)'ʆŸqHNjŸ.T^+𝑎d𝑏X`1
(2)'ɋɃZ“5”DāNjŸ.T^+𝑎d𝑏X`1
(3)ů𝑎= 8dȬ5öŸqHŹe 1d'ʆŸqHNjŸaɋɃZ“5”DāNjŸs
Āā(1)4𝑎−8𝑏
(2)8𝑎−4𝑏
(3)ʆŸqHNjŸe16dɋɃZ“5”DāNjŸ56
ĂěĊĜn):;STdƶƅƷĢ&a'(Ąďd%HO/lj
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NJSTs
.11¢£D 1 aD 2 ½¬
ʆŸqHŸe𝑎−𝑏dŹe𝑎−3𝑏d÷iìøù¼;s
.21¢£DHd&¼;¶Ñ
.31¢£öŸqHŹe 1dÑČʆŸqHŹe 2d×µ𝑎−3𝑏= 2dì𝑎= 8Ã'¬ bd÷iÃ
.11.21×'NjŸd¼;¶Ñs
ąĄ.11Ą
∵ʆŸqHŸe𝑎−𝑏dŹe𝑎−3𝑏d
∴ʆŸqHNjŸ = 2 (𝑎−𝑏)+(𝑎−3𝑏) = 4𝑎−8𝑏
.21Ą
ɋɃZ“5”DāNjŸe
4𝑎+ 4(𝑎−𝑏) = 8𝑎−4𝑏
.31Ą
∵öŸqHŹe 1dÑČʆŸqHŹe 2d
∴𝑎−3𝑏= 2d
∵𝑎= 8dt8−3𝑏= 2d
∴𝑏= 2d
ó.11ѽ
ʆŸqHNjŸ = 4𝑎−8𝑏= 4 × 8−8 × 2 = 16d
ó.21ѽ
ɋɃZ“5”DāNjŸ = 8𝑎−4𝑏= 8 × 8−4 × 2 = 56s
[ 14-3.24-25 ĐđĒē·ħĨʡʢ·Ėł1ödfgČŅʣ 12d27d36d45d108d…¾ƣɿ÷
Òǧ 3 )sæèdɿ÷×+ēZĝaÒǧ 3 )dÀÁ¾ɿ÷Òǧ 3 )
sʤQēdfgѵʥѾOPíĚǎs
µÄedůÄȀ ēZļe𝑎,𝑏dt{|ú¾Äe𝑎𝑏dÙ𝑎𝑏
= 10𝑎+ 𝑏= 9𝑎+ (𝑎+ 𝑏)dʦ÷d9𝑎Òǧ 3 )dÕădů𝑎+ 𝑏Òǧ 3 )dÀÁ9𝑎+ (𝑎+ 𝑏)dÒǧ 3
)d¶𝑎𝑏Òǧ 3 )s
¢£ē«ȝɦdĄĀė&M
(1)ė&åEdÒǧ 3 )+___________.·B 1
①25②225③1025s
(2)T^𝑎 𝑏 𝑐X`û𝑎𝑏𝑐= ___________.³E𝑎ʧd𝑏Ȁd𝑐1
(3)3ŕē«¿AdʨȰĸŃ
û𝑎𝑏𝑐×+ĝaÒǧ 9 )dÀÁ¾ûÒǧ 9
)s
Āā(1)②
(2)100𝑎+ 10𝑏+ 𝑐
(3)ʩĄĂ
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ĂěĊĜ&µ*)d)89STsƶƅƷĢvČčĈĄď
.11¼;åēZĝadůÒǧ 3 )dtĻÒǧ 3 )d£ăğàá¶Ñ
.21¢£ÊČʪœÑ½𝑎𝑏𝑐= 100𝑎+ 10𝑏+ 𝑐
.31𝑎𝑏𝑐= 100𝑎+ 10𝑏+ 𝑐= 9(11𝑎+ 𝑏) + (𝑎+ 𝑏+ 𝑐)d¢£ÊČʪœº»ȝɦqâ¶ÑʥŃs
ąĄ.11 ∵2 + 5 = 7d7 ~Òǧ 3 )d
∴25 ~Òǧ 3 )
∵2 + 2 + 5 = 9d9 Òǧ 3 )d
∴225 Òǧ 3 )
∵1 + 0 + 2 + 5 = 8d8 ~Òǧ 3 )d
∴1025 ~Òǧ 3 )
ĆÒǧ 3 )+ 225s
.21𝑎𝑏𝑐= 100𝑎+ 10𝑏+ 𝑐s
.31𝑎𝑏𝑐= 100𝑎+ 10𝑏+ 𝑐= 9(11𝑎+ 𝑏) + (𝑎+ 𝑏+ 𝑐)d
∵9(11𝑎+ 𝑏)Òǧ 3 )d
ů𝑎+ 𝑏+ 𝑐Òǧ 3 )dt9(11𝑎+ 𝑏) + (𝑎+ 𝑏+ 𝑐)Òǧ 3 )d¶𝑎𝑏𝑐Òǧ 3 )d
∴û𝑎𝑏𝑐×+ĝaÒǧ 9 )dÀÁ¾ûÒǧ 9 )s
【题型15 与绝对值有关的化简】
15.24-25ĐđĒė·Ʊɕ·ȆĊȰ1x+Ďd|𝑥−5| + |𝑥−7| + |𝑥+ 6| + |𝑥−9|Ðö(
s
Āā17
ĂěĊĜnUV(FG%d)89:;dʫȦʬTFGqâ=>^+UV(_d
ƶƅƷĢUV(FG%Ąďss
LjTUV(FG%d¶'ĠĈ−6d5d7d9 ƯʭÐö(s
ąĄĄ
Řăe xd
ð%d|𝑥−5| + |𝑥−7| + |𝑥+ 6| + |𝑥−9|X` x ĈĠX`−6d5d7d9 ĈƯʭťaÐöd
∴óʬѽd5 ≤𝑥≤7dƎ½Ðö(d
∴|𝑥−5| + |𝑥−7| + |𝑥+ 6| + |𝑥−9| = 𝑥−5 + 7−𝑥+ 𝑥+ 6 + 9−𝑥= 17d
ĆĀāe
17s
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[ 15-1.24-25 ĐđĒē·Ƣƞ·Ėł1ÊČ𝑎d𝑏d𝑐ʬēʮD×`d×VSĈļe Ad
BdCs=>
|𝑎+ 𝑏|−2|𝑐−𝑏|−|𝑐−𝑎| =
s
Āā3𝑐−𝑏/𝑏−3𝑐
Ă本题考查的是整式的加减,熟知整式的加减实质上是合并同类项是解答此题的关键.
先根据各点在数轴上的位置判断出各点的符号及绝对值的大小,再去绝对值符号,合并同类项即可.
ąĄ解:∵由图可知,𝑐< 𝑏< 0 < 𝑎,且|𝑎| > |𝑏|,
∴𝑎+ 𝑏> 0,𝑐−𝑏< 0,𝑐−𝑎< 0,
∴|𝑎+ 𝑏|−2|𝑐−𝑏|−|𝑐−𝑎|
= 𝑎+ 𝑏+ 2(𝑐−𝑏) + 𝑐−𝑎
= 𝑎+ 𝑏+ 2𝑐−2𝑏+ 𝑐−𝑎
= 3𝑐−𝑏,
故答案为:3𝑐−𝑏.
[ 15-2.24-25 ĐđĒē·ŜǢ·ĖE11sÊČd+Ď𝑎 𝑏 𝑐ʬēʮD×`d
.11=>
|3𝑎+ 𝑏|−|𝑐−2𝑎| + |𝑐+ 2𝑏| =
.21ů𝑎,𝑐ÄɝËgɿʯd𝑥$ʰ
xd|𝑥−𝑎| + |𝑥−𝑐|+Ðö(dÐö(e
s
.31.21ʪœėdůʱČ𝑥 𝑦ǫǬ |𝑥−𝑎|+|𝑥−3|
|𝑦−2|+|𝑦−𝑐| = 6dt𝑥+ 2𝑦Ðp(
s
Āā
𝑎+ 3𝑏+ 2𝑐
−1 ≤𝑥≤1
2
7
ĂěĊĜ=>UV(dÄĈĞƯʭd)89:;d¢£ʬàápöd_ d
ƷĢUV(%dĄďs
ąĄĄ
.11óDÑČ
𝑐< 0 < 𝑎< 𝑏d|𝑐| < 𝑏d
∴3𝑎+ 𝑏> 0,𝑐−2𝑎< 0,𝑐+ 2𝑏> 0d
∴Ì = 3𝑎+ 𝑏−2𝑎+ 𝑐+ 𝑐+ 2𝑏= 𝑎+ 3𝑏+ 2𝑐
ĆĀāe
𝑎+ 3𝑏+ 2𝑐
.21∵𝑎,𝑐ÄɝËgɿʯd
∴𝑎= 1,𝑐= −1d
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∵|𝑥−𝑎| + |𝑥−𝑐| = |𝑥−1| + |𝑥−(−1)|X`ʬēX`𝑥ĠX`1a−1Ưʭad
∴−1 ≤𝑥≤1xd|𝑥−𝑎| + |𝑥−𝑐|+Ðö(e
1−(−1) = 2
ĆĀāe
−1 ≤𝑥≤12
.31ó.21Č
1 ≤𝑥≤3xd|𝑥−𝑎| + |𝑥−3|+Ðö(e3−1 = 2d
−1 ≤𝑦≤2xd|𝑦−2| + |𝑦−𝑐|+Ðö(e2−(−1) = 3d
∵|𝑥−𝑎|+|𝑥−3|
|𝑦−2|+|𝑦−𝑐| = 6d
∴|𝑥−𝑎| + |𝑥−3| = 2d|𝑦−2| + |𝑦−𝑐| = 3d
∴𝑥Ðp(e 3d𝑦Ðp(e2d
∴𝑥+ 2𝑦Ðp(e
3 + 2 × 2 = 7
ĆĀāe
7s
[ 15-3.24-25 ĐđĒē·ȅʲʳĪ·ĖE1+Ď adbdc ʬēVSĈʮD×`dė&
OP
①𝑎𝑏𝑐> 0②𝑎−𝑏+ 𝑐< 0③
|𝑎|
𝑎+
|𝑏|
𝑏+
|𝑐|
𝑐= −1④|𝑎+ 𝑏|−|𝑏−𝑐| + |𝑎−𝑐| = −2𝑐³EíĚOP
. 1
As4
Bs3
Cs2
Ds1
ĀāB
ĂěĊĜnLjTʬøùv¼;dHO/0ŃĚUV(ř=>âtdĄďsõ
óʬȭȮ½¬ 𝑏< 𝑐< 0 < 𝑎,∣𝑏∣> ∣𝑐∣> ∣𝑎∣d£ăğ4¼;ʴʥ¶Ñs
ąĄĄ
∵óʬѽ
𝑏< 𝑐< 0 < 𝑎,∣𝑏∣> ∣𝑐∣> |𝑎|d
∴𝑎𝑏𝑐> 0d①íĚ
𝑎−𝑏+ 𝑐> 0d②ũŪ
∣𝑎∣
𝑎+
𝑏
∣𝑏∣+
∣𝑐∣
𝑐= 1−1−1 = −1d③íĚ
∣𝑎+ 𝑏∣−∣𝑏−𝑐∣+ 𝑎−𝑐∣= −𝑎−𝑏−(𝑐−𝑏) + 𝑎−𝑐
= −𝑎−𝑏−𝑐+ 𝑏+ 𝑎−𝑐
= −2𝑐d
④íĚ
ľēdíĚe3s
Ćć
Bs
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【题型16 探索与表达规律(数字变化类)】
16“ĈʵfʶNJdʷ+ÑǤ”ʸʆŘ¼¥IJEd“ɠNʹ”öʺŘ¼nJK¥IJ
VðÖƉ&Ä) mdn ºė#Iøùʉ
Æ 1 Öʉi½Ġ)E mdnd𝑛−𝑚
Æ 2 Öʉi½Ġ)E mdnd𝑛−𝑚d−𝑚
Æ 3 Öʉi…
³ʉ#te
ÝÖʉʻ84d¡TēÖʉ½ĠÐł495³4döʺ¦¾¥IJ
ʼŏe“ʽǪ”ʾʿs
tĻ“ʽǪ”ʾʿÆ 2023 Öʉi½Ġ)Eå4ĝa. 1
As𝑚+ 𝑛
Bsm
Cs𝑛−𝑚
Ds2𝑛
ĀāD
ĂõğÅĂ 5 Öʉdѽ)ʈÝĽÖȑƜdì'ĄÆĽÖʉi×+)ĝae
𝑚+ 𝑛+ 𝑛−𝑚−𝑚−𝑛−𝑛+ 𝑚= 0dO/2023 ÷ 4 = 505 ⋅⋅⋅3dǺƧѽĀās
ąĄĄ
Æ 1 Öʉi½Ġ)ʈ mdnd𝑛−𝑚
Æ 2 Öʉi½Ġ)ʈ mdnd𝑛−𝑚d−𝑚
Æ 3 Öʉi½Ġ)ʈ mdnd𝑛−𝑚d−𝑚d−𝑛
Æ 4 Öʉi½Ġ)ʈ mdnd𝑛−𝑚d−𝑚d−𝑛d−𝑛+ 𝑚
Æ 5 Öʉi½Ġ)ʈ mdnd𝑛−𝑚d−𝑚d−𝑛d−𝑛+ 𝑚d𝑚
⋅⋅⋅⋅⋅⋅
džLJѽ
µē)ʈÝȃÖȑƜd
∵2023 ÷ 6 = 337 ⋅⋅⋅1d
∴Æ 2023 Öʉi½Ġ)Eå4ĝa<Æ 1 Öʉi½Ġ)ʈĝavřd
∴¾ae𝑚+ 𝑛+ 𝑛−𝑚= 2𝑛d
Ćć D
ĈĉěĊĜ)89:;d#IJKdƷĢJKqâd0ťO,7#I0ˀ¥:
TĄěďs
[ 16-1.24-25 ĐđĒē·ħĨûŃ·ĖE1+&º#IƉ&
𝑏d2𝑏−𝑎d3𝑏−2𝑎d4𝑏−3𝑎d
5𝑏−4𝑎d……vưÄ¡2)důÆ 4 (e 8dt 7 ae. 1
As28
Bs56
Cs84
Ds112
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ĀāB
ĂěĊĜn)89STdĎĄ%dǛĠ#IíĚ&¬;Ąďsó%½dvư
Ä¡𝑏−𝑎dõ¼;¬ 7 ad¢£Æ 4 (e 8 ѽ4𝑏−3𝑎= 8dì)
Ã'(¶ÑĄĀs
ąĄĄ
ó%½dvưÄ¡(2𝑏−𝑎)−𝑏= 𝑏−𝑎d
∴ 7 e
𝑏d𝑏+ (𝑏−𝑎)d𝑏+ 2(𝑏−𝑎)d𝑏+ 3(𝑏−𝑎)d𝑏+ 4(𝑏−𝑎)d𝑏+ 5(𝑏−𝑎)d𝑏+ 6(𝑏−𝑎)d
∴ 7 a = 7 × 𝑏+ (1 + 2 + 3 + 4 + 5 + 6) × (𝑏−𝑎) = 28𝑏−21𝑎d
∵Æ 4 (e 8d
∴4𝑏−3𝑎= 8d
∴28𝑏−21𝑎= 7(4𝑏−3𝑎) = 7 × 8 = 56d
∴ 7 ae 56s
Ćć
Bs
[ 16-2ʫȦ d¨©[½>ˁŃnsÑT
𝑑2
5 −
𝑐3
2 +
𝑎2𝑏2
27 mX`“
Ǿ
ɾ
二˂
Ï
ɽ
三⊥
ÏĐ
ō
二Ŏ
二”
.Ȑćɿ 1905 đ˃˄ʚ˅ě1sȭȮ³E#Id¦“
ȃ
ĽŎ
二⊥
Ï
ō
二˂
û
Ŏ
二”=>i½. 1
As−
𝑎2
2 + 𝑏2
Bs
𝑎2
2 + 𝑏2
Cs−
𝑎2
2 +
𝑏2
3
Ds
𝑎2
2 +
𝑏2
3
ĀāD
ĂěĊĜn&d)89dĎĄ%Ąďs¢£§d&¶Ñs
ąĄĄ
¢£%dÑČ“
ȃ
ĽŎ
二⊥
Ï
ō
二˂
û
Ŏ
二”X`e
4𝑏2
6 +
𝑎2
2 −
𝑏2
3 d
=>½
𝑎2
2 +
𝑏2
3 d
Ćć
Ds
[ 16-3.2025·śŜǑǒ·ûƗ1ˆˆaˇˇV 5 í)øù#IJKdˆˆ"¬ûȎʇ
𝑎1, 𝑎2, 𝑎3(𝑎1 < 𝑎2 < 𝑎3)dˇˈ"¬ÄȎʅ
𝑎4, 𝑎5(𝑎4 < 𝑎5)dů𝑎1 + 𝑎2 + 𝑎3 = 𝑎4 + 𝑎5dt
1
3
(2𝑎1 + 𝑎3 + 𝑎4) +
1
2(𝑎2 + 2𝑎5)(Ò. 1
Asǧ 6 )
Bsǧ 7 )
Csǧ 8 )
Dsǧ 9 )
ĀāB
ĂěĊĜ)89:;STd¦ûȎʇaÄȎʅTX`dLjTÊČ
ʪœĨʗqAd=>ȐĶXYdO/ʅʇǎĂ½¬O.
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ąĄĄ
∵ûȎʇ
𝑎1, 𝑎2, 𝑎3(𝑎1 < 𝑎2 < 𝑎3)dÄȎʅ
𝑎4, 𝑎5(𝑎4 < 𝑎5)
t 𝑎2 = 𝑎1 +2,𝑎3 = 𝑎1 +4d𝑎5 = 𝑎4 +2d
∴𝑎1 + 𝑎1 +2 + 𝑎1 +4 = 𝑎4 + 𝑎4 +2d
∴3𝑎1 +6 = 2𝑎4 +2d
∴𝑎4 =
1
2(3𝑎1 + 4)d
∴
1
3(2𝑎1 + 𝑎3 + 𝑎4) +
1
2(𝑎2 + 2𝑎5)
= 1
3 2𝑎1 + 𝑎1 + 4 +
3
2 𝑎1 + 2 + 1
2 (𝑎1 + 2 + 2𝑎4 + 4)
= 1
3
9
2 𝑎1 + 6 + 1
2 (𝑎1 + 2 + 3𝑎1 + 4 + 4)
= 3
2 𝑎1 + 2 + 2𝑎1 + 5
=
7
2𝑎1 +7d
Ř𝑎1 = 2𝑘d𝑎4 =
1
2(3𝑎1 + 4) = 3𝑘+ 2eʅdt𝑘eíʅd
∴
7
2𝑎1 +7 = 7𝑘+ 7 = 7(𝑘+ 1)d
∴
1
3(2𝑎1 + 𝑎3 + 𝑎4) +
1
2(𝑎2 + 2𝑎5)(Òǧ7)d
Ćć
B
【题型17 探索与表达规律(图形变化类)】
17.24-25 ĐđĒē·Ƣƞ·ijƚȰ1DdÝDāƴóźŸvřˉ ˊÄˋíqHº#IȚ
Ƨd»ă#IdÆ n DāEˊˋíqHŕˉˋíqHN
.T^ n _X`1s
Āā(4𝑛+ 3)
ĂěĊĜnDH3#IdíĚ¼;ÊČDHEˋíqHŕˉˋíïôN0½Ġ#IĄ
ďsLjT§¬ûDHȵǛ#IdȌĥˊˋíqH=ťíqH-ˉˋíqHdƧˉˋí
qHÆ 1 e 1dÆÏe 2dóăȵǛ#IdťŨǛĠź<ˉˋíqHĝĞc¶Ñdð
ă3ʊdȵǛ#Is
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ąĄĄ
Æ 1 DHˉ ˊÄˋíqHģ3 × 3d³Eˉˋ 1 dˊˋ(3 × 3−1)d
Æ 2 DHˉ ˊÄˋíqHģ3 × 5d³Eˉˋ 2 dˊˋ(3 × 5−2)d
Æ 3 DHˉ ˊÄˋíqHģ3 × 7d³Eˉˋ 3 dˊˋ(3 × 7−3)d
ðă3ʊd
Æ n DHˉ ˊÄˋíqHģ3(2𝑛+ 1)d³Eˉˋ n dˊˋ3(2𝑛+ 1)−𝑛= (5𝑛+ 3)d
……
∴Æ n DāEˊˋíqHŕˉˋíqHN5𝑛+ 3−𝑛= (4𝑛+ 3)d
ĆĀāe∶ (4𝑛+ 3)s
[ 17-1ÊČdDdfgѵTŸƳv2ſˌɛº#IȚˍíNźHǜDādDā①é 8
¢ſˌɛdDā②é 15 ¢ſˌɛd…dºă#IdˍĨÆ n Dāé
¢ſˌɛdˍĨÆ 2020 D
āé
¢ſˌɛs
Āā
7𝑛+ 1
14141
Ă¢£DHaZ#I /0234ǎǐd¼;½Æ n Dāſˌɛbd좣ǎ
ǐ¼;d¶Ñ½ĠĀās
ąĄ¢£%dÆ 1 Dāſˌɛ+
8 × 1 + 0 = 8¢
Æ 2 Dāſˌɛ+
8 × 2 + 1 = 8¢
Æ 3 Dāſˌɛ+
8 × 3 + 2 = 8¢
…
Æ n Dāſˌɛ+
8 × 𝑛+(𝑛−1) ¢d¶7𝑛+ 1¢
∴Æ 2020 Dāſˌɛ+
7 × 2020 + 1 = 14141¢
ĆĀāe
7𝑛+ 1d14141s
ĈĉěĊĜnZaDH#I /0234 ČčĄďƶƅƷĢZaDH#
IǎǐdǺƧ¸'Ąs
[ 17-2.24-25 ĐđĒē·śŜˎū·ƃƄƅj1ºD×`#IˍíqH
ˍöíqHé 4
¢öɛdˍÄöíqHé 7 ¢öɛdtˍ 2024 ¾ƣöíqHéöɛ.ÿÿ1
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As6071 ¢
Bs6072 ¢
Cs6073 ¢
Ds6074 ¢
ĀāC
ĂěĊĜn#I
DH[=sĄďȌĥåíqHˏcdǛ¬³E#Is
{¿džLJ<ťO½¬#I
íqHÝʻ8 1dſˌɛʻ8 3dóă'¬Æ𝑛DHxéſˌ¢
d÷iÃ'(¶Ñs
ąĄĄ
ˍ 2 íqHé4 + 3 × 1 = 7¢ſˌɛ
ˍ 3 íqHé4 + 3 × 2 = 10¢ſˌɛ
…d
ˍ𝑛¾ƣíqHé4 + 3(𝑛−1) = (3𝑛+ 1)¢ſˌɛd
ˍ 2024 ¾ƣíqHé3 × 2024 + 1 = 6073¢ſˌɛs
Ćć
Cs
[ 17-3.24-25 ĐđĒė·ƓƔƔȅ·ȆĊȰ1Dópöv2★ǜDHdÆ①DHE+ 4
★dÆ②DHE+ 7 ★dÆ③DHE+ 10 ★dÆ④DHE+ 13 ★d…dºă#Iƭė5d
Æ 89 DHEģ+NŖ★ŗ.
1
As265
Bs266
Cs267
Ds268
ĀāD
ĂăġĊĜnDH[=#IsːˑȭȮDH[=dǛĠ#IdLjT#I'Ąs
ąĄĄ
Æ①DHE+3 × 2−2 = 4★d
Æ②DHE+3 × 3−2 = 7★d
Æ③DHE+3 × 4−2 = 10★d
Æ④DHE+3 × 5−2 = 13★d
…d
Æ n DHEģ+3 × (𝑛+ 1)−2 = (3𝑛+ 1)★s
𝑛= 89xd3 × 89 + 1 = 268d
Ćć
Ds
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