Question

因式分解:(x-y)^2(m-n)+(x+y)^2(n-m)

Answer 1

答：

(x-y)^2(m-n)+(x+y)^2(n-m)

=(m-n)*[(x-y)^2-(x+y)^2]

=(m-n)*(x-y+x+y)*(x-y-x-y)

=(m-n)*(2x)*(-2y)

=-4(m-n)xy