Question

If a^2+b^2+c^2=20 and a+b+c=0 findab+bc+ca

Answer 1

a^2+b^2+c^2=(a+b+c)^2 - 2ab - 2bc - 2ca

since, a+b+c=0,

20= - 2 (ab+bc+ca)

-10=ab+bc+ca

hope it helps mark me as brainliest