x2+2xy+y2x2y+xy2-x2-2xy+y2x2y-xy2．

题型：解答题难度：一般来源：不详

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

．