Question

if a2+b2+c2=20 and a+b+c=0 then find ab+bc+ca

Answer 1

$<b>Hey mate$

here's ur answer

$lets \: use \: \\ (a + b + c ) ^{2}$
$= a ^{2} + b ^{2} + c ^{2} \\ + 2ab + 2bc + 2ca$
➡↗✨rest refer to the attachment