Question

If a2 + b2 + c2 = 29 and ab + bc + ca = 26, then the value of a + b + c can be ______.​

Answer 1

Answer:

If a2 + b2 + c2 = 29 and ab + bc + ca = 26, then the value of a + b + c can be ___9___.

Step-by-step explanation:

Given (a + b + c) = 9 and (ab + bc + ca) = 26 (a + b + c)2 = 92 ⇒ a2 + b2 + c2 + 2(ab + bc + ca) = 81 ⇒ a2 + b2 + c2 + 2(26) = 81 ⇒ a2 + b2 + c2 + 52 = 81 ⇒ a2 + b2 + c2 = 81 − 52 = 29

Answer 2

Answer:

9

Step-by-step explanation:

a2+b2+c2 = 29

ab+bc+ca = 26

a+b+c = ?

let us square the eq. a+b+c

= (a+b+c)^2

= a2+b2+c2+2ab+2bc+2ca

= a2+b2+c2+2(ab+bc+ca)

putting the values,....

=29+2(26)

=29+52

=81

(a+b+c)^2 = 81

= a+b+c = root(81)

a+b+c = 9