已知:A=2x^3-xyz,B=y^3-z^3+xyz,C=-x^3+2y^2-xyz,且(x+1)^2+|y-1|+|z|=0,求A-[2B-3(C-A)]的值
问题描述:
已知:A=2x^3-xyz,B=y^3-z^3+xyz,C=-x^3+2y^2-xyz,且(x+1)^2+|y-1|+|z|=0,求A-[2B-3(C-A)]的值
答
(x+1)^2+|y-1|+|z|=0(x+1)^2=0 x+1=0 x=-1y-1=0 y=1z=0A=2x^3-xyz=2*(-1)^3-0=-2B=y^3-z^3+xyz=1^3-0+0=1C=-x^3+2y^2-xyz=1+2*1-0=3A-[2B-3(C-A)]=-2-[2*1-3(3+2)]=-2-2+15=11