计算:(x加y)(x的立方减xy减y的立方).(要具体计算过程)

问题描述:

计算:(x加y)(x的立方减xy减y的立方).(要具体计算过程)

(x+y)(x^3-xy-y^3)
=x(x^3-xy-y^3)+y(x^3-xy-y^3)
=x^4-x^2y-xy^3+x^3y-xy^2-y^4
=x^4+x^3y-x^2y-xy^2-xy^3-y^4负a的2次方(a加3)减a的2次方(a的2次方减2a加2),其中a等于负2。(要具体解答过程)-a^2(a+3)-a^2(a^2-2a+2)=-a^2(a+3-a^2+2a-2)=-a^2(-a^2+3a+1)=a^2(a^2-3a-1)=(-2)^2*[(-2)^2-3(-2)-1]=4*(4+6-1)=4*9=36