Question

(x-2y)^3+(2y-z)^3+(z-x)^3

Answer 1

Given x-2y+2y-z+z-x=0

then (x-2y)^3+(2y-z)^3+(z-x)^3=3(x-2y)(2y-z)(z-x)  

(using identity if a+b+c=0,a^3+b^3+c^3=3abc )

Hope  this help you