Question

If a 2 + b2 + c2 = 250 and ab + bc + ac = 3. Find the value of a + b + c

Answer 1

(a+b+c)2=a2+b2+c2+2(ab+bc+ca)
(a+b+c)2=250+2*3
(a+b+c)2=256
(a+b+c)  = sqr root of 256
               =16