题目内容
(1)
+
(2)
-
.
| a+3b |
| a+b |
| a-b |
| a+b |
(2)
| 2xy2+1 |
| (x-y)2 |
| 1+2x2y |
| (y-x)2 |
分析:(1)根据同分母的分式相加的法则:分母不变,分子相加.注意最后结果要约分;
(2)由于(x-y)2=(x-y)2,根据同分母的分式相减的法则:分母不变,分子相减.注意最后结果要约分..
(2)由于(x-y)2=(x-y)2,根据同分母的分式相减的法则:分母不变,分子相减.注意最后结果要约分..
解答:解:(1)
+
=
=
=2;
(2)
-
=
=
=
.
| a+3b |
| a+b |
| a-b |
| a+b |
=
| a+3b+a-b |
| a+b |
=
| 2(a+b) |
| a+b |
=2;
(2)
| 2xy2+1 |
| (x-y)2 |
| 1+2x2y |
| (y-x)2 |
=
| 2xy2+1-1-2x2y |
| (x-y)2 |
=
| 2xy(y-x) |
| (x-y)2 |
=
| 2xy |
| y-x |
点评:本题是基础题,考查了分式的加减,同分母的分式相加的法则:分母不变,分子相加;同分母的分式相减的法则:分母不变,分子相减.
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