2023北京西城区初一(上)期末数学答案
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学年度第一学期期末试卷 第1页（共5页）
北京市西城区2022—2023学年度第一学期期末试卷
七年级数学答案及评分参考
2023.1
一、选择题（共16分，每题2分）
题号 1 2 3 4 5 6 7 8
答案 C B A B D C D B
二、填空题（共16分，每题2分）
9．4.07． 10．125． 11．9−． 12．答案不唯一，如：4
−ab
．
13．3． 14．5−． 15．(0.950)−a
． 16．3
；答案不唯一，如：
三、解答题（共68分，第17题18分，第18-19题，每题6分，第20题11分，第21题
6分，第22-24题，每题7分）
17．解：（1）12(6)(28)−+−−−
＝18(28)−−− ······································································································· 2分
＝10． ·················································································································· 4分
（2）815
()(9)
54−−
＝8151
549 ·········································································································· 3分
＝2
3． ···················································································································· 4分
（3）375
()(48)
16246−−+−
＝91440+− ········································································································· 3分
＝17−． ················································································································ 5分
（4）227
3(1)(2)
8−+−−
＝1
9()4
8−+−
····································································································· 3分 学年度第一学期期末试卷 第2页（共5页）
＝1
9
2−− ··············································································································· 4分 ＝1
9
2−． ··············································································································· 5分
18．解：（1）点C在直线AB外； ································ 1分
（2）如图所示； ················································ 3分
（3）∵DC＝AD＋AC，AD＝AB，
∴DC＝AB＋AC．
∵AB＋AC ＞ BC，（ 两点之间，线段最短 ）
······································· 5分
∴DC ＞ BC． ····························································································· 6分
19．解：222
3(2)(37)10−−++xyyxy
222
363710=−−−+xyyxy ························································································ 2分
2
4=−+xy． ················································································································· 4分
当1
4=−x，5=y时，
原式21
4()5
4=−−+ ···································································································· 5分
125=+
26=． ··················································································································· 6分
20．（1）7202(33)−=−xx
解：去括号，得 72066−=−xx． ·············································································· 1分
移项，得 76620+=+xx． ·················································································· 3分
合并同类项，得 1326=x． ·················································································· 4分
系数化1，得 2=x． ····························································································· 5分
（2）2331
1
52−−
=+xx
解：去分母，得 2(23)5(31)10−=−+xx
． ································································ 2分
去括号，得 4615510−=−+xx． ······································································· 3分 学年度第一学期期末试卷 第3页（共5页）
移项，得 4156510−=−+xx． ··········································································· 4分
合并同类项，得 1111−=x． ················································································· 5分
系数化1，得 1=−x． ··························································································· 6分
21．解：（1）①如图所示； ············································ 1分
②∵∠EOD＝90°，
∴∠EOC＋∠ COD ＝90°． ············ 2分
∵∠AOB＝∠COD，
∴∠EOC＋∠ AOB ＝90°． ············ 3分
∵∠AOC＝90°，
∴∠EOC＋∠AOE＝90°．
∴∠ AOB ＝∠ AOE ．（ 同角的余角相等 ） ······································· 5分
∴OA平分∠EOB．
（2）OC，EOD． ······································································································ 6分
22．方法一：3x，4(2)+x； ································································································ 2分
解：设每台A型机器一天生产x件产品．
依题意列方程，得 34(2)
57+
=xx
． ······································································ 4分
解得 40=x． ·········································································································· 5分
所以3
24
5=x
．·········································································································· 6分
答：每台A型机器一天生产40件产品，每箱装24件产品． ··································· 7分
方法二：5x，7x； ········································································································ 2分
解：设每箱装x件产品．
依题意列方程，得 57
2
34+=xx
．········································································· 4分
解得 24=x． ·········································································································· 5分
所以5
40
3=x
．·········································································································· 6分
