题目内容
计算与化简:
(1)
+(1-
)÷(1+
)
(2)(
)2•(-
)3÷(-
)4.
(1)
| 3-a2 |
| a2+2a+1 |
| 1 |
| a+1 |
| 1 |
| a-1 |
(2)(
| c |
| ab |
| b |
| ac |
| b |
| a |
分析:(1)现将括号内的部分通分,再将除法转化为乘法约分,然后通分相加;
(2)先将分子、分母分别乘方,再把除法转化为乘法,然后约分.
(2)先将分子、分母分别乘方,再把除法转化为乘法,然后约分.
解答:解:(1)原式=
+(
-
)÷(
+
)
=
+
•
=
+
=
+
=
=
.
(2)原式=-
•
•
=-
=-
.
| 3-a2 |
| (a+1)2 |
| a+1 |
| a+1 |
| 1 |
| a+1 |
| a-1 |
| a-1 |
| 1 |
| a-1 |
=
| 3-a2 |
| (a+1)2 |
| a |
| a+1 |
| a-1 |
| a |
=
| 3-a2 |
| (a+1)2 |
| a-1 |
| a+1 |
=
| 3-a2 |
| (a+1)2 |
| a2-1 |
| (a+1)2 |
=
| 2 |
| (a+1)2 |
=
| 2 |
| a2+2a+1 |
(2)原式=-
| c2 |
| a2b2 |
| b3 |
| a3c3 |
| a4 |
| b4 |
=-
| a4b3c2 |
| a5b6c3 |
=-
| 1 |
| ab3c |
点评:本题考查了分式的混合运算,熟悉因式分解是解题的关键.
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