文档内容
南宁市 2023~2024 学年度秋季学期期末学业质量监测
七年级数学参考答案和评分标准
一、选择题(共12小题,每小题3分,共36分)
题号 1 2 3 4 5 6 7 8 9 10 11 12
答案 A C B D B A C C D A C D
二、填空题(本大题共6小题,每小题2分,共12分)
13. 4 14. 9.53 15. 两点之间,线段最短. 16. 60 17. 6 18. -2
三、解答题(本大题共8小题,共72分)
19. (本题满分8分)
解:(1)原式=1+(-5)+9+4.................................................................................................................................1分
=9...........................................................................................................................................................4分
(2)原式=6+4÷2................................................................................................................................................7分
=8...........................................................................................................................................................8分
20. (本题满分8分)
解:(1)3xx82 ...............................................................................................................................................2分
2x10...................................................................................................................................................3分
x5 ...................................................................................................................................................4分
(2)(3 x1)2x6..........................................................................................................................................5分
3x32x6...........................................................................................................................................6分
3x2x63.......................................................................................................................................7分
x3 ................................................................................................................................................8分
21. (本题满分8分)
解:原式=6a2b-2a-3a2b+2a......................................................................................................................2分
=6a2b-3a2b......................................................................................................................................4分
=3a2b.................................................................................................................................................6分
1
当a=2,b= 时,
3
1
原式 =3×22× .......................................................................................................................................7分
3
=4.......................................................................................................................................................8分
22. (本题满分8分)
解:(1)
{#{QQABJQoEogCoAAAAAAhCAwV6CAMQkAAAAAoGgEAEsAAAyQFABAA=}#}①如图,线段AB为所求作线段;.................................................................................................................1分
②如图,线段BC为所求作线段;.................................................................................................................3分
③如图,线段AD为所求作线段;.................................................................................................................5分
(2)由(1)得BC=AB=5,AD=m=3...............................................................................................................6分
∴DB=AB-AD=2..............................................................................................................................7分
∵CD=DB+BC
∴CD=2+5=7.......................................................................................................................................8分
23. (本题满分10分)
解:(1)该公司本周共销售绣球:100×7+10+12+(-15)+(-6)+14+(-18)+13............................4分
=710(个).................................................................................................................................................5分
答:该公司本周共销售绣球710个.................................................................................................................6分
(方法不唯一,若学生分步列式计算,全对就得满分,未全对则按步骤酌情给分)
(2)该公司一周的总销售额:710×20 ...........................................................................................................8分
=14200(元).....................................................................................................................................................9分
答:该公司一周的总销售额为14200元...................................................................................................................10分
24. (本题满分10分)
【操作实践】
(1)解:由折叠得∠B′OC=∠BOC=x, .............................................................................................................1分
∴∠BOB′=2∠BOC=2x,..................................................................................................................................2分
∵x=35°,
∴∠BOB′=2×35°=70°, ..................................................................................................................................3分
∵∠AOB=180°,
∴∠AOB′=∠AOB-∠BOB′=180°-70°=110°................................................................................................4分
【拓广探索】
(2)(方法不唯一)
由折叠得∠A′OD=∠AOD,∠B′OC=∠BOC=x,
∴∠BOB′=2∠BOC=2x,..................................................................................................................................6分
∵OB′平分∠BOD,
∴∠BOD=2∠BOB′=4x,..................................................................................................................................7分
∵∠AOB=180°,
∴∠AOD=∠AOB-∠BOD=180°-4x............................................................................................................8分
{#{QQABJQoEogCoAAAAAAhCAwV6CAMQkAAAAAoGgEAEsAAAyQFABAA=}#}(3) 32°......................................................................................................................................................................10分
x x
25. (本题满分10分)
解:(1)胜一局积3分,平一局积1分,负一局积 分....................................................................................3分
(2)选手E的胜局积分不能等于平局积分的四−倍1. 理由:
设选手E负x局,则胜2x局,平(12-x-2x)局,..............................................................................4分
可得胜局积分为3×2x分,平局积分为(12-x-2x)分.
3×2x=4×(12-x-2x) ......................................................................................................................6分
8
解得x= .......................................................................................................................................8分
3
8
因为x的值必须是整数,所以x= 不符合实际..........................................................................................9分
3
从而选手E的胜局积分不能等于平局积分的四倍. ....................................................................................10分
26.(本题满分10分)
解:(1)分针绕点O旋转形成的角的度数是6°×30=180°,...............................................................................1分
时针绕点O旋转形成的角的度数是30°×7+0.5°×30=225°,....................................................................2分
所以∠α=225°-180°=45°..............................................................................................................................3分
答:当时为7时30分时,α的度数是45°;............................................................................................................4分
(说明:①用其它方法解答,理由充分,给4分)
(2)设王老师外出散步用了x分钟,依题意得....................................................................................................5分
分针绕点O旋转形成的角的度数是6x°,
时针绕点O旋转形成的角的度数是30°×7+0.5x°=(0.5x+210)°,
情况1,若分针绕点O旋转形成的角的度数小于时针绕点O旋转形成的角的度数时
(0.5x+210)-6x=90..........................................................................................................................6分
240
解得x ............................................................................................................................7分
11
情况2,若分针绕点O旋转形成的角的度数大于时针绕点O旋转形成的角的度数时
6x-(0.5x+210)=90............................................................................................................................8分
600
解得x ............................................................................................................................9分
11
答:王老师外出散步的时间是
240 分钟或600
分钟................................................................................................10分
11 11
(说明:①列方程时用绝对值的方式,正确给满分,②不用方程,理由充分,每写对一种情况给3分)
{#{QQABJQoEogCoAAAAAAhCAwV6CAMQkAAAAAoGgEAEsAAAyQFABAA=}#}