题目内容
| 2xy |
| x2-y2 |
| x |
| x+y |
| x |
| y-x |
分析:先将分式进行通分,分母化为x2-y2,然后将分子相加减,提取公因式2xy,分子分母约去x+y,便可得出结果.
解答:解:
+
-
=
=
=
=
=
| 2xy |
| x2-y2 |
| x |
| x+y |
| x |
| x-y |
| 2xy+x(x-y)+x(x+y) |
| x2-y2 |
=
| 2xy+x2-xy+x2+xy |
| x2-y2 |
| 2xy+2x2 |
| (x-y)(x+y) |
=
| 2x(x+y) |
| (x-y)(x+y) |
| 2x |
| x-y |
点评:本题考查了分式的加减法,要求学生熟记异分母分式相加减时,先通分化为同分母分式,后约分的规则,属于基础题.
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