Question

L.
7. If a+b+c=9 and ab+bc+ca=23 then a2+b2+c2=
​

Answer 1

Answer:

a² + b² + c² = 35

Explanation:

a + b + c = 9

ab + bc +ca = 23

by identity,

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

a² + b² + c² = (9)² - 2 * 23

a² + b² + c² = 81 - 46

a² + b² + c² = 35