Question

已知A=2x的三次方-xyz,B=y的三次方-z的三次方-xzy,且(x+1)的二次方+ly-1l

Answer 1

A=2x^3-xyz B=y^3-z^3-xyz C=-x^3+2y^3-xyz (x+1)^2+|y-1|+|z|=0

(x+1)^2+|y-1|+|z|=0

x+1=0 y-1=0 z=0

x=-1 y=1 z=0

A=-2 B=1 c=1+2=3

A-（2B-3C）=-2-(2-9)=9