Помогите решить (x-y)(x+2y)(2x-y)
(x-y)(x+2y)(2x-y)=(x²-xy+2xy-2y²)(2x-y)=(x²+xy-2y²)(2x-y)=2x³+2x²y-4xy²-x²y-xy²+2y³=2x³+x²y-5xy²+2y³