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2025 年中考第二次模拟考试(江苏淮安卷)
数学·参考答案
第Ⅰ卷
一.选择题(本大题共有8小题,每小题3分,共24分.在每小题给出的四个选项中,恰有一项是符合题
目要求的,请将正确选项前的字母代号填涂在答题卡相应位置上)
题号 1 2 3 4 5 6 7 8
答案 A A D D B C D D
第Ⅱ卷
二.填空题(本大题共有8小题,每小题3分,共24分.不需写出解答过程,请把答案直接写在答题卡相
应位置上)
9.x<2
10.21
1
11.
3
12.8√2
3√10
13.
10
14.2.5
15.﹣6
6√5
16.
5
三.解答题(本大题共有11小题,共102分.请在答题卡指定区域内作答,解答时应写出必要的文字说明、
证明过程或演算步骤)
17.(10分)
1 −1
解:(1)√4+(−2023) 0−( ) +|−2|
3
=2+1﹣3+2=2;···············································································5分
(2)解不等式x+1>0得,x>﹣1,
x−2
解不等式x≤ +2得,x≤2,
3
∴不等式组的解集为:﹣1<x≤2.···················································10分
18.(8分)
2(m−n) m2−2mn+n2
解:原式= ÷
m m
2(m−n) m
= •
m (m−n) 2
2
= ,·········································································5分
m−n
当m=3,n=﹣1时,
2
原式=
3−(−1)
1
= .············································································8分
2
19.(8分)
解:(1)闭合其中任何一个开关,灯泡都会发光,
故灯泡发亮是必然事件;
故选C;········································································3分
(2)在图1的电路图中,新增一个开关组B,在A、B两个开关组中各闭合一个开关,
列表如下:
S S S
1 2 3
S S ,S S ,S S ,S
4 4 1 4 2 4 3
S S ,S S ,S S ,S
5 5 1 5 2 5 3
S S ,S S ,S S ,S
6 6 1 6 2 6 3
共有9种等可能的结果,其中小灯泡发亮的结果有3种,
3 1
∴小灯泡发亮的概率为:P= = .···················································8分
9 3
20.(10分)
解:(1)m=200×34%=68,······················································2分
n=46÷200×100%=23%,························································4分故答案为:68,23%.
(2)被调查的高中学生视力情况的样本容量为14+44+60+82+65+55=320,
故答案为:320.·····································································6分
200−(46+68)+320−(65+55)
(3)26000× =14300(名),
200+320
答:估计该区有14300名中学生视力不良,··············································8分
建议:学校可以多开展用眼知识的普及,规定时刻做眼保健操(答案不唯一).···············10分
21.(8分)
证明:∵四边形ABCD是平行四边形,
∴AD∥BC,
∴∠AEO=∠CFO,
在△AEO和△CFO中,
{∠AOE=∠COF
∠AEO=∠CFO,
AE=CF
∴△AEO≌△CFO(AAS),
∴OE=OF.·····································································8分
22.(8分)
解:(1)由图象可得,
甲车的速度为:75÷1=75(km/h),
乙车的速度为:75×2.3÷(2.5﹣1)=125(km/h),
m=2.5+(2.5﹣1)=2+1.5=4,
故答案为:75,125,4;····························································3分
(2)当x=4时,y=1.5×(75+125)=300,
设两边相遇后,乙车在返回过程中,y与x的函数表达式为y=kx+b,
{2.5k+b=0
把(2.5,0),(4,300)代入得: ,
4k+b=300
{ k=200
解得; ,
b=−500
∴y=200x﹣500(2.5≤x≤4);·························································5分
(3)当y=100时,100=200x﹣500,
解得:x=3,
3×75=225(km),∴甲车的行驶路程为:225km.·························································8分
23.(8分)
解:(1)如图,等腰直角△ABE,∠A=90°如图所示;
···························································2分
1
(2)如图,△CDF、tan∠CFD= 如图所求;··········································5分
2
(3)由图知, ,
EF=√42+12=√17
故答案为:√17.·····································································8分
24.(8分)
解:(1)如图2,过点C作CE⊥AB于点E,则∠CEA=90°,
CE √3
在Rt△ACE中,sinA= =sin60°= ,
AC 2
√3 √3
∴CE= AC= ×24=12√3(cm),
2 2
答:点C到AB的距离为12√3cm;······················································4分
(2)如图2,过点D作DF⊥CE于点F,过点D作DG⊥AB于点G,
则四边形DFEG是矩形,
∴EF=DG,
由(1)可知,CE=12√3cm,∠ACE=90°﹣∠BAC=30°,
∵∠ACD=55°,
∴∠DCE=∠ACD﹣∠ACE=25°,
在Rt△DCF中,CF=CD•cos25°≈10×0.906=9.06(cm),
∴EF=CE﹣CF=12√3−9.06≈11.7(cm),
∴DG=EF=11.7cm,
答:点D到AB的距离约为11.7cm.······················································8分25.(10分)
(1)证明:连接OE,
∵CD与 O相切于点E,
∴∠OED⊙=90°,
∴∠D+∠DOE=90°,
∵OE=OA,
∴∠A=∠AEO,
∴∠D=∠AEO,
∴AEO+∴DOE=90°,
∴AE⊥OD,
∴^AF=^EF,
∴F是AE的中点;·····································································5分
(2)解:∵∠A=∠C,∠A=∠D,
∴∠C=∠D,
∴OC=OD,
∵OE⊥CD,
∴∠COE=∠DOE,
由(1)知,^AF=^EF,
∴∠AOF=∠DOE,
1
∴∠COE=∠DOE=∠AOD= ×180°=60°,
3
∵OE=3,
∴DE=√3OE=3√3,1 60π×32 9√3 3π
∴阴影部分的面积=S△DOE ﹣S△扇形FOE =
2
×3×3√3−
360
=
2
−
2
.
9√3 3π
故答案为: − .·······························································10分
2 2
26.(12分)
(1)把A(﹣2,0),B(4,0)代入y=ax2+bx+6中,得,
{4a−2b+6=0
,
16a+4b+6=0
3
{a=−
解得 4,
3
b=
2
3 3
∴抛物线的函数表达式为y=− x2+ x+6.
4 2
2
把x=0代入y= x−4中,得y=﹣4,
3
∴E(0,﹣4),
2
把y=0代入y= x−4中,得x=6,
3
∴D(6,0);···········································································3分
(2)设点M的横坐标为m,
3 3 2
∴点M的坐标为(m,− m2+ m+6)(0<m<4),点N的坐标为(m, m−4).
4 2 3
如图,过点M作MP⊥y轴于点P,过点N作NQ⊥y轴于点Q.∵MN⊥x轴,
∴MN∥y轴,
∴PM=NQ,
又∵CM=EN,
∴Rt△MCP≌Rt△NEQ,
∴CP=EQ,∠MCP=∠NEQ.
如图1,当点M在点C的上方时,
∵∠MCP=∠NEQ,
∴MC∥EN,
∴四边形CENM为平行四边形,
∴MN=CE=10,
3 3 2
∴− m2+ m+6−( m−4)=10,
4 2 3
10
解得m =0(舍去),m = .
1 2 9
如图2,当点M在点C的下方时,CP=EQ,3 3 2
∴6−(− m2+ m+6)= m−4−(−4),
4 2 3
26
解得m =0(舍去),m = .
1 2 9
10 26
综上所述,点M的横坐标为 或 .······················································8分
9 9
(3)存在,点G的坐标为(﹣4,2),
如图3,设MN与x轴交于点H,
当△MHD≌△DOE时,四边形MDEG是正方形,
∴当MH=OD,DH=OE时,四边形MDEG是正方形,
∴MH=OD=6,DH=OE=4,
∴OH=2,
3 3
把x=2代入y=− x2+ x+6中,得y=6,
4 2
∴点M的坐标为(2,6),
根据平移性质可得点G的坐标为(﹣4,2).·············································12分27.(12分)
(1)证明:∵四边形ABCD是正方形,
∴AD∥BC,
∴∠GEC=∠BCE,
∵四边形ABCE沿直线CE折叠,
∴∠BCE=∠GCE,
∴∠GEC=∠GCE,
∴EG=CG;············································································2分
(2)证明:如图1,
连接CF,
∵四边形ABCD是正方形,
∴∠B=∠ADC=∠CDF=90°,BC=CD,
∵四边形ABCE沿直线CE折叠,
∴CM=BC,∠CMF=∠B=90°,
∴∠CMF=∠CDDF=90°,CM=CD,
∵CF=CF,
∴△CMF≌△CDF(HL),
∴DF=FM,
∴∠FDM=∠FMD,
∵F是MN的中点,
∴FN=FM,
∴FN=FD,
∴∠FNF=∠FDN,
∵∠FMD+∠FND+(∠FDN+∠FDM)=180°,
∴2∠FDN+2∠FDM=180°,∴∠FDN+∠FDM=90°,
∴∠MDN=90°;·······································································8分
(3)解:如图2,连接CF,交DM于O,
设DF=FN=FM=a,则CD=CM=BC=MN=2a,
设FG=x,
∵∠GMF=∠CDG=90°,∠G=∠G,
∴△GMF∽△GDC,
FG GM FM 1
∴ = = = ,
CG DG CD 2
∴CG=2FG=2x,
∴DG=x+a,CG=2x,CD=2a,
在Rt△CDG中,CD2+DG2=CG2,
∴(2a)2+(x+a)2=(2x)2,
5
∴x=﹣a(舍去)或x= a,
3
10 8
∴CG=2x= a,DG=x+a= a,
3 3
10
由(1)知,EG=CG= a,
3
10 8 2
∴DE=EG﹣DG= a− a= a,
3 3 3
∵CM=CD,DF=FM,
∴DM⊥CF,
∴∠FOM=90°,
由(2)知,∠MDN=90°,
∴∠MDN=∠FOM,
∴CF∥DQ,∵DF∥CB,
∴四边形DQCF是平行四边形,
∴CQ=DF=a,
DE 2
∴ = .·······································································12分
CQ 3