X^3（x-2y）+y^3（2x-y）
=x^4-2x^3y+2xy^3-y^4
=(x^2+y^2)(x+y)(x-y)-2xy(x^2-y^2)
=(x^2+y^2-2xy)(x+y)(x-y)
=(x-y)^3(x+y)
手机提问的朋友在客户端右上角评价点【满意】即可.