(x+y)(x-y)+(x-y)^2-(6x^2×y÷2y-2xy^2÷2y)其中x=-3,y=1/3

题目

(x+y)(x-y)+(x-y)^2-(6x^2×y÷2y-2xy^2÷2y)其中x=-3,y=1/3

答案

答：
(x+y)(x-y)+(x-y)^2-(6x^2×y÷2y-2xy^2÷2y)
=x^2-y^2+x^2-2xy+y^2-(3x^2-xy)
=2x^2-2xy-3x^2+xy
=-x^2-xy
=-x(x+y)
=-(-3)*(-3+1/3)
=-9+1
=-8