Question

if a + b + C is equal to 12 and a square + b square + c square is equal to 50 find ab + bc + ca

Answer 1

Answer:47

Explanation:

as a+b+c=12 and a2+b2+c2=50

As per formula

(a+b+c)2=a2+b2+c2+2ab+2bc+2ca

now putting values

(12)2=50+2(ab+bc+ca)

(144-50)/2=ab+bc+ca

94/2=ab+bc+ca

ab+bc+ca=47