Question

If a^2+b^2+c^2=80 and a+b+c =20, then find the value of ab+bc+ca, then find the value of ab+bc+ca

Answer 1

HOPE THIS WILL HELP U.

Answer 2

a^2+b^2+c^2=(a+b+c)^2-2(ab+bc+ca)
80=400-2(ab+ba+ca)
=160