Question

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

Answer 1

原式=-x^2-3/2x^2+1/3y+2/3-2x^2

=-9/2x^2+1/3y+2/3

把x=-3,y=1/3带入

x^2=9

原式=-9/2*9+1/3*1/3+2/3

=-715/18