Question

is a square + b square + c square equal to 50 and AB+ BC + CA equal to 47 find A+B+C

Answer 1

(a+b+c) ^2 =a^2+b^2+c^2+2 (ab +bc+can)
=50+2*47
(a+b +c) ^2 =50+94=144
(a+b +c) =root of 144=12

Answer 2

a²+b²+c² = 50
ab+bc+ca = 47

(a+b+c)² = a²+b²+c²+2ab+2bc+2ca
a+b+c = [50+2×47]½
= √144
=12

a+b+c = 12

hope it helps you
@di