题目内容
化简求值:(x2-4 |
x2-4x+4 |
x-2 |
x+2 |
x |
x-2 |
分析:先通分,再按四则运算进行即可,最后选择一个使分式的分母不为0的数代入求值.
解答:解:原式=[
-
]×
=
×
-
×
=
-
=
=
,
∵x≠±2,0,
∴x取1,
原式=
=
.
(x+2)(x-2) |
(x-2)2 |
x-2 |
x+2 |
x-2 |
x |
=
(x+2)(x-2) |
(x-2)2 |
x-2 |
x |
x-2 |
x+2 |
x-2 |
x |
=
x+2 |
x |
(x-2)2 |
x(x+2) |
=
(x+2)2-(x-2)2 |
x(x+2) |
=
8 |
x+4 |
∵x≠±2,0,
∴x取1,
原式=
8 |
1+4 |
8 |
5 |
点评:本题考查了分式的化简求值,是基础知识要熟练掌握.
练习册系列答案
相关题目