Question

If + + = 12 and a2 + b2 + c2 = 66, find the value of + + .



please answer​

Answer 1

Answer:

use the eqn

use the eqn

Step-by-step explanation:

Answer 2

Answer:

We know that (a+b+c)

2

=a

2

+b

2

+c

2

+2ab+2bc+2ca

i.e. (a+b+c)

2

=a

2

+b

2

+c

2

+2(ab+bc+ca)

Substituting, the given values we get,

12

2

=66+2(ab+bc+ca)

⇒144−66=2(ab+bc+ca)

⇒78=2(ab+bc+ca)

⇒ab+bc+ca=

2

78

=39