Question

if a + b + C is equal to 15 and a square + b square + c square is equal to 625 find a b + BC + AC

Answer 1

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

225 = 625 + 2(ab + bc +ca)

ab + bc + ca = -200

Answer 2

a+b+c=15

a²+b²+c²=625

Acc. to identity

(a+b+c)² = a²+b²+c²+2ab+abc+2ca

15² = 625 + 2(ab+bc+ca)

225-625=2(ab+bc+ca)

-400\2 =(ab+bc+ca)

-200=ab+bc+ca

Mark it as the brainliest plzzz.