Question

a(b-c)+b(c-a)+c(a-b)

Answer 1

LHS= a(b-c) +b(c-a) +c(a-b)
= ab-ac+bc-ab+ac-bc
=0
Simple

Answer 2

a (b-c)+b (c-a)+c (a-b)
ab-ac+bc-ab+ac-bc
=0