题目内容
计算:(1)| 2a |
| a2-4 |
| 1 |
| a-2 |
(2)
| x+1 |
| x |
| 2x2-1 |
| 2x |
| x |
| 2 |
分析:(1)最小公分母为(a-2)(a+2),通分后合并,再约分即可;
(2)先把括号内通分,得到原式=
÷
,再转化成乘法后约分即可.
(2)先把括号内通分,得到原式=
| x+1 |
| x |
| (x-1)(x+1) |
| 2x |
解答:解:(1)原式=
-
=
=
;
(2)原式=
÷
=
•
=
.
| 2a |
| (a-2)(a+2) |
| a+2 |
| (a-2)(a+2) |
=
| a-2 |
| (a-2)(a+2) |
=
| 1 |
| a+2 |
(2)原式=
| x+1 |
| x |
| (x-1)(x+1) |
| 2x |
=
| x+1 |
| x |
| 2x |
| (x-1)(x+1) |
=
| 2 |
| x-1 |
点评:本题考查了分式的混合运算:只有加减运算的,先把分式通分,再分子进行加减运算,最后化成最简分式;有乘除运算的,先计算括号内,然后把分子分母都进行因式分解,约分后合并即可.
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