问题 解答题
x2+2xy+y2
x2y+xy2
-
x2-2xy+y2
x2y-xy2
答案

原式=

(x+y)2
xy(x+y)
-
(x-y)2
xy(x-y)

=

x+y
xy
-
x-y
xy

=

x+y-x+y
xy

=

2y
xy

=

2
x

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