Question

(ii) a+b+c= 9 311 ab + bc + ca= 26​

Answer 1

Step-by-step explanation:

Given, a+b+c=9 and ab+bc+ca=26.

We know, (a+b+c)2=a2+b2+c2+2ab+2bc+2ca

⇒(a+b+c)2=a2+b2+c2+2(ab+bc+ca).

Putting the values here, we get,

(9)2=a2+b2+c2+2(26)

⇒81=a2+b2+c2+52

⇒a2+b2+c2=81−52=29.