Question

Plz answer friends I had asked same question for many no one is answering..... Give step by step answer

Answer 1

Step-by-step explanation:

w/k,

(a+b+c)²=a²+b²+c²+2(ab+bc+ac)

(15)²=83+2(ab+bc+ac)

225-83=2(ab+bc+ac)

142=2(ab+bc+ac)

ab+bc+ac=71