题目内容
化简计算:
(1)1-
÷
(2)
÷(1-
).
(1)1-
| a-1 |
| a |
| a2-1 |
| a2+2a |
(2)
| x-2 |
| x2 |
| 2 |
| x |
分析:(1)先把除法运算化为乘法运算,再把分式的分子、分母因式分解,然后约分得到原式=1-
,最后进行通分即可;
(2)先把除法运算化为乘法运算,然后约分即可.
| a+2 |
| a+1 |
(2)先把除法运算化为乘法运算,然后约分即可.
解答:解:(1)原式=1-
•
=1-
=
=-
;
(2)原式=
÷
=
•
=
.
| a-1 |
| a |
| a(a+2) |
| (a+1)(a-1) |
=1-
| a+2 |
| a+1 |
=
| a+1-(a+2) |
| a+1 |
=-
| 1 |
| a+1 |
(2)原式=
| x-2 |
| x2 |
| x-2 |
| x |
=
| x-2 |
| x2 |
| x |
| x-2 |
=
| 1 |
| x |
点评:本题考查了分式的混合:先把分式的分子或分母因式分解,再进行通分或约分,得到最简分式或整式.
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