题目内容
计算:(1)
| a3 |
| a+1 |
| a |
| a+1 |
| m2 |
| m-1 |
| 4a |
| a2-1 |
| 1+a |
| 1-a |
| a2b |
| -cd3 |
| 2a |
| d3 |
| c |
| 2a |
分析:(1)同分母通分,再将分子因式分解与分母约分;
(2)通分,将分子化简;
(3)将分母因式分解,通分;
(4)先乘方,再乘除.
(2)通分,将分子化简;
(3)将分母因式分解,通分;
(4)先乘方,再乘除.
解答:解:(1)
-
,
=
,
=
,
=a2-a;
(2)
-(m+1),
=
,
=
;
(3)
+
,
=
-
,
=
,
=
;
(4)(
)3÷
•(
)2,
=-
•
•
,
=
.
| a3 |
| a+1 |
| a |
| a+1 |
=
| a3-a |
| a+1 |
=
| a(a+1)(a-1) |
| a+1 |
=a2-a;
(2)
| m2 |
| m-1 |
=
| m2-(m+1)(m-1) |
| m-1 |
=
| 1 |
| m-1 |
(3)
| 4a |
| a2-1 |
| 1+a |
| 1-a |
=
| 4a |
| (a+1)(a-1) |
| (a+1)2 |
| (a+1)(a-1) |
=
| -(a-1)2 |
| (a+1)(a-1) |
=
| 1-a |
| 1+a |
(4)(
| a2b |
| -cd3 |
| 2a |
| d3 |
| c |
| 2a |
=-
| a6b3 |
| c3d9 |
| d3 |
| 2a |
| c2 |
| 4a2 |
=
| a3b3 |
| 8cd6 |
点评:本题考查分式的混合运算,关键是通分,合并同类项,注意混合运算的运算顺序.
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