题目内容：

-m²n(x-y)n次方+mn²(x-y)n-1次方

优质解答

-m²n(x-y)^n+mn²(x-y)^(n-1)
mn[n(x-y)^(n-1)-m(x-y)^n]
=mn(x-y)^(n-1)[n-m(x-y)]
=mn(my-mx+n)(x-y)^(n-1)