(x+3)^2+(x+2)(x-2)-2x^2,其中x=-1/3

问题描述:

(x+3)^2+(x+2)(x-2)-2x^2,其中x=-1/3
y(x+y)+(x-y)^2-(x+y)(x-y)其中x=-1/3 y=3

(x+3)^2+(x+2)(x-2)-2x^2
=x^2+6x+9+x^2-4-2x^2
=6x+5
=-2+5
=3