[]江苏省徐州市睢宁县2017届九年级5月中考模拟考试数学试题（扫描版）

$$ 中考模拟测试 数学选择题参考答案 第 1 页（共 5 页） 21 9．2 10． 11．9 12．65 13． 35° 51.05 10 题号 1 2 3 4 5 6 7 8 选项 B C D A D B A A x ≤1 17． 3 5 2  18． 1＜x＜0  14． 3 15．26 16． 19．（1）原式= ··········································································································· 3 分 2 1 9  = ． ········································································································· 5 分 6 （2）原式= 1 1 2( 1)( ( 1)( 1) ( 1)( 1) x x x x x x x x   1)x           ················································· 7 分 = 2 2( 1)( ( 1)( 1) x x x x x      1) ············································································ 8 分 = 4 x ·············································································································· 10 分 20．（1） 1, 4, 1a b c     2 4 2b ac  0 ············································································································ 2 分 4 2 5 2 x   ············································································································ 4 分 ∴ 1 2 5x   2 2 5x   ··········································································· 5 分 （2） 解不等式①得：x≥1 ······························································································· 6 分 解不等式②得：x＞2 ······························································································· 7 分 ······························································ 8 分 ∴不等式组的解集为 x＞2 ······································································· 10 分 21．（1） ·································································································· 4 分 7, 7.5, 4.2a b c   （2） 从平均成绩可以看出甲乙二人成绩相等，均为 7 环；从中位数可以看出甲射中 7 环以 上的次数比乙小；从众数可以看出乙射中 8 环次数多而甲射中 7 环多；从方差可以看出甲的成绩 比乙稳定，如果选一位参