Question

If a + b + c = 12 and ab + bc + ca = 22, find a2 + b2 +c2​

Answer 1

Answer:

given a+b+c=12 , ab+bc+ca=22

wkt,(a+b+c)²=a²+b²+c²+2(ab+bc+ca)

=> (12)²=a²+b²+c²+2×22

=> a²+b²+c²= 144-44=100

Answer 2

$a + b + c = a}^{2} + b }^{2} + c { }^{2} + 2(ab + bc + ca) \\ 12 }^{2} = 22 + 2(ab + bc + ca) \\ 144 = 22 + 2(ab + bc + ca) \\ 144 - 22 = 2(ab + bc + ca \\ 122 \div 2 = (ab + bc + ca) \\ (ab + bc + ca) = 61$