Question

solve it fast :if a+b+c=12 and a²+b²+c²=100, find ab+bc+ca.

please help me fast. ​

Answer 1

Answer:

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

or, 12^2 = 100 +2(ab+bc+ac)

or, (144 -100)/2= ab+bc+ac

or, ab+bc+ac = 22

Answer 2

This is the solution bro.