If `a= x - y, b= y - z` and `c =z - x` then the value of `a^3+b^3+c^3`

If b+c = 2x, c+a =2y and a +b =2z then value of a^(3) +b^(3) +c^(3) is

Given a=x/(y-z),b=y/(z-x), and c=z/(x-y), where x,y,z and are not all zero,then the value of ab+bc+ca is 0 b.1 c.-1 none of these