2012徐州数学中考试题(5)

参考答案

一选择题 1 C 2 B 3 A 4 B 5 B 6 D 7 C 8 D 二填空题 9..a(x 4)(x 4), 10 31, 85, 11 -2,

17

≤x≥x 5 ,13. 12 .22 , 14 .110°，15 一 三，16 .90°，17. 7,18. B、603、6n 3；

三 解答题

19（1）解：原式=3 —

=1+2-1

=2 ………………………6分

1

—2³ ....4分

2

x 1(x 1)2

（2）解：原式= -------------2分 x(x 1)(x 1)

x 1(x 1)(x 1)

-----------3分 2

x(x 1)

=

x 1

-----------------4分 x

2 13

当x=2时， 原式== -----------------6分

22

20 .

x 2y 1①

.

3x 2y 11②

①＋②，得4x＝12，解得：x＝3．----------------------------3分 将x＝3代入①，得9－2y＝11，解得y＝－1．------------5分

x 3

所以方程组的解是 ．----------------------------------6分

y 1

21 （本题6分）

解：（1） BE CF，

BF BE EF，CE CF EF，

······················································································································· 1分 BF CE． ·

四边形ABCD是平行四边形，

······················································································································· 2分 AB DC． ·

在△ABF和△DCE中，

AB DC，BF CE，AF DE，

········································································································· 3分 △ABF≌△DCE． ·