若vx+v(y-1)+v(z-2)=1/2(x+y+z),则(x-z)^3=v是根号,帮帮忙吧!

Question

若vx+v(y-1)+v(z-2)=1/2(x+y+z),则(x-z)^3=
v是根号,帮帮忙吧!

Answer 1

vx+v(y-1)+v(z-2)=1/2(x+y+z)
==>[x-2（根号x）+1]+[y-1-2（根号y-1）+1]+[z-2-2根号(z-2）＋1]=0
==>（根号x-1）^2+[根号(y-1)-1]^2+[（根号z-2）-1]^2=0
==>根号x-1=0,根号(y-1)-1=0,根号(z-2)-1=0
==>x=1,y=2,z=3
==>(x-z)^3=-8