Question

if a+b+c=7 and ab+bc+ca=20 then find the value of a square+b square+c square

Answer 1

We know ,
(a+b+c)² = a²+b²+c²+2(ab+bc+ac)
(7)² = a²+b²+c²+2(20)
a²+b²+c² = 49-30 = 9

Answer 2

hope this answer may help you..............