Question

If x+y+z=0, show that x cube+y cube+z cube =3xyz

Answer 1

first
x+y+z=0
x+y= -z--->(1)
so cubing on both sides on 1st equation

=>(x+y)cube= -(z)cube
(by using identity (a+b)cube=a cube + b cube +
3ab(a+b)
now substitute in that form you Wil get answer
substitute in x+y place take minus z