Question

a+b+c=12 and a^2+b^2+c^2=64

Answer 1

Answer : 80

Solution :
_________

Given that :

$a + b + c = 12 \: and \: {a }^{2} + {b}^{2} + {c}^{2} = 64$

As we know that :

${(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(ab + bc + ca) \\ \\ = > {(12)}^{2} = 64 + 2(ab + bc + ca) \\ \\ = > 2(ab + bc + ca) = 144 - 64 = 80$

So, the answer will be 80

Answer 2

What's ur question ???....

The question is incomplete....

Though, I think u wanna ask the value of
(ab + bc + ca).....


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

So,

12^2 = 64 + 2(ab + bc + ca)

Hence,

ab + bc +ca is 40