Question

Proof a³+b³+c³=3abc ,if a+b+c=0

Answer 1

lhs=a^3+b^3+c^3

a^3+b^3+c^3-3abc+3abc

(a+b+c)(a^2+b^2+c^2-ac-bc-ab)+3abc

LHS=3abc=RHS. (:a+b+c=0)