题目内容
化简分式:| 2a2+3a+2 |
| a+1 |
| a2-a-5 |
| a+2 |
| 3a2-4a-5 |
| a-2 |
| 2a2-8a+5 |
| a-3 |
分析:直接通分计算较繁,先把每个假分式化成整式与真分式之和的形式,再化简将简便得多.
解答:解:
-
-
+
=(2a+1)+
-(a-3)-
-(3a+2)+
+(2a-2)-
=[(2a+1)-(a-3)-(3a+2)+(2a-2)]+(
-
+
-
)
=
-
+
-
=
-
=
.
| 2a2+3a+2 |
| a+1 |
| a2-a-5 |
| a+2 |
| 3a2-4a-5 |
| a-2 |
| 2a2-8a+5 |
| a-3 |
=(2a+1)+
| 1 |
| a+1 |
| 1 |
| a+2 |
| 1 |
| a-2 |
| 1 |
| a-3 |
=[(2a+1)-(a-3)-(3a+2)+(2a-2)]+(
| 1 |
| a+1 |
| 1 |
| a+2 |
| 1 |
| a-2 |
| 1 |
| a-3 |
=
| 1 |
| a+1 |
| 1 |
| a+2 |
| 1 |
| a-2 |
| 1 |
| a-3 |
=
| 1 |
| (a+1)(a+2) |
| 1 |
| (a-2)(a-3) |
=
| -8a+4 |
| (a+1)(a+2)(a-2)(a-3) |
点评:本题考查了分式的加减运算,难度较大.本题的关键是正确地将假分式写成整式与真分式之和的形式.
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