山东省济南市槐荫区2020-2021学年八年级上学期期末考试数学试题答案

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八年级数学试题参考答案与评分标准
一、选择题
题号
1
2
3
4
5
6
7
8
9
10
11
12
答案
D
A
C
B
A
C
B
D
A
C
B
D
二、填空题
13. (－3，5)
14. x<－2
15. 乙
16. 40°或100°
17.
34
18.
3
2
3
三、解答题
19.解：（1）原式=
2
2
2
3-24
······················································· 2 分
=
=
2
2
7
········································································ 3 分
（2）解：①+②得：7x=14
x=2 ·································································· 4 分
把x=2 代入①得：2×2+3y=7
解得：y=1 ······························································· 5 分
原方程组的解为：
1
2
y
x
···································································· 6 分
20.解： 解不等式①得：
153 xx
62 x
3x
························································ 1 分
解不等式②得：
223 xx
322 xx
1x
1x
··························································· 3 分
所以，不等式组的解集为：
31 x
········································· 5 分
所以，不等式组的整数解为：0，1，2 ········································ 6 分
第 2 页(共 6 页)
21.解：（1）图形正确 ············································································· 2 分
如图 1所示：正方形即为所求； ······························································· 3 分
（2）作图痕迹正确 ················································································ 5 分
如图 2，点 D即为所求． ········································································ 6 分
22.解：∵AB＝AC，
∴∠ABC＝∠ACB， ··········································································· 1 分
∵BD 平分∠ABC，CE 平分∠ACB，
∴∠ABD＝
1
2
∠ABC，∠ACE＝
1
2
∠ACB， ············································· 2 分
∴∠ABD＝∠ACE， ··········································································· 3 分
∵AD⊥BD，AE⊥CE
∴∠D＝∠E＝90°， ········································································· 4 分
在△ADB 与△AEC 中，
DD
ABD ACE
AB AC
 
 
， ············································································ 6 分
∴△ADB≌△AEC， ··········································································· 7 分
∴AD＝AE． ····················································································· 8 分
23.解：(1)∵OB＝2，OA＝1，
∴A的坐标为（1，0）， B的坐标为（0，2）， ·········································· 1 分
设AB 的解析式为 y＝kx+2 ，
将A坐标代入得 0＝k+2，
图1
图2
山东省济南市槐荫区2020-2021学年八年级上学期期末考试数学试题答案.pdf

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作者：envi 分类：初中 价格：3知币 属性：6 页 大小：385.29KB 格式：PDF 时间：2025-04-22

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