xx-y•y2x+y-x4yx4-y4÷x2x2+y2

题型：解答题难度：一般来源：不详

x

x-y

•

y2

x+y

-

x4y

x4-y4

÷

x2

x2+y2

答案

原式=

xy2

(x-y)(x+y)

-

x4y

(x2+y2)(x2-y2)

×

x2+y2

x2

=

xy2

(x-y)(x+y)

-

x2y

(x-y)(x+y)

=

xy2-x2y

(x-y)(x+y)

=

xy(y-x)

(x-y)(x+y)

=-

xy

x+y

．
故答案为-

xy

x+y

．