(-x-2y)(x2-2xy+4y2)等于多少

问题描述:

(-x-2y)(x2-2xy+4y2)等于多少

(-x-2y)(x2-2xy+4y2)
=-(x+2y)*(x2-2xy+4y2)
=-x^3-(2y)^3
=-x^3-8y^3