(x+y)^2(x-y)+(x+y)(x-y)^2
=(此山梁唯告x+y)森运(x-y)(x+y+x-y)
=(x+y)(x-y)*2x
=2x^3-2xy^2
=(x+y)(x-y)(x+y+x-y)
=2x(x+y)(x-y)
(x+y)^2(x-y)+(x+y)(x-y)^2
=(x+y)(x-y)【(x+y)+(x-y)】此山梁森运唯告
=(x+y)(x-y)*2x
=2x^3-2xy^2
(x+y)^2(x-y)+(x+y)(x-y)^2
=(x+y)(x-y)(x+y+x-y)
=2x(x^2-y^2)
=2x^3-2xy^2