Question

If x+y+z=o and x2+y2+z2=35 find the value of x3+y3+z3-3xyz

Answer 1

This is very simple:

apply the identity of
a3+ b3 +c3- 3abc=(a +b+ c )(.........)
It is given that x y z=0 then
x3 +y3+z3-3xyz=0

Hope u got that

Answer 2

using identity

∵a³+b³+c³-3abc=(a+b+c)(a²+b²+c²-ab-bc-ca)

∴x³+y³+z³-3xyz=(x+y+z)(x²+y²+z²-xy-yz-zx)

x³+y³+z³-3xyz=0(x²+y²+z²-xy-yz-zx)

⇒x³+y³+z³-3xyz=0