Question

If a+b+c = 6, a2 + b2 + c2 = 26 find the value of (ab + bc + ca)​

Answer 1

Answer:

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

(6)^2 = 26 + 2 ( ab + bc + ca)

36 = 26 + 2 ( ab + bc + ca)

36 - 26 = 2 (ab + bc + ca )

10/2 = ( ab + bc + ca )

5 = ( ab + bc + ca)

Hence , (ab + bc + ca) = 5.

Answer 2

Answer:

ab+Bc+ca =5

Explanation:

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

this is the formula of the answer