化简(-x)(x^2-2xy-y^2)-y(xy+2x^2-y^2) ,(9a^2-6ab+b^2)÷(3a-b)-2(a+b)^2,

化简(-x)(x^2-2xy-y^2)-y(xy+2x^2-y^2) ,(9a^2-6ab+b^2)÷(3a-b)-2(a+b)^2,
化简(-x)(x^2-2xy-y^2)-y(xy+2x^2-y^2) ,(9a^2-6ab+b^2)÷(3a-b)-2(a+b)^2,

化简(-x)(x^2-2xy-y^2)-y(xy+2x^2-y^2) ,(9a^2-6ab+b^2)÷(3a-b)-2(a+b)^2,
(-x)(x^2-2xy-y^2)-y(xy+2x^2-y^2)
=-x^3+2x^2y+xy^2-xy^2-2x^2y+y^3
=-x^3+y^3
(9a^2-6ab+b^2)÷(3a-b)-2(a+b)^2,
=(3a-b)^2÷(3a-b)-2(a+b)^2
=3a-b-2a^2-4ab-2b^2