Question

If a+b+c=25 and a2+b2+c2=375 find ab+bc+ca

Answer 1

Answer:

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

Putting the value of the given equations.

(25)^2 = 375 + 2(ab+bc+ca)

625 = 375 + 2(ab+bc+ca)

625 - 375 = 2(ab+bc+ca)

250 = 2(ab+bc+ca)

250/2 = ab+bc+ca

125 = ab+bc+ca

Step-by-step explanation:

Hope it helps you...