Question

If a+b+c =0 and ab +bc+ca = 40 find a²+ b²+c²

Answer 1

Explanation:

${(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(ab + bc + ca)$

$0 = {a}^{2} + {b}^{2} + {c}^{2} + 2(40)$

${a}^{2} + {b}^{2} + {c}^{2} = - 80$

Answer = -80