Question

if a + b + c = 9 and ab + bc + ca = 23 , then the value of a square + b square + c square equal to​

Answer 1

Answer:

58

Step-by-step explanation:

Using identity :-

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

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

=> a^2 + b^2 + c^2 = (9)^2 - (23)

=> a^2 + b^2 + c^2 = 81 - 23

=> a^2 + b^2 + c^2 = 58

Hope this helps

Answer 2

Answer:

a²+b²+c²= 35

Step-by-step explanation:

Given :- a+b+c = 9__(i)

ab+bc+ca = 23__(ii)

Now in eq_(i) Squaring both sides, we get

=(a+b+c)²= (9) ²

= (a+b+c) (a+b+c) = 81

= a²+b²+ c²+ 2ab + 2bc + 2ca = 81

= a²+b²+c² + 2( ab+bc+ca) = 81

= a²+b²+c²+ 2 ( 23 ) = 81

= a²+b²+c² + 46 = 81

= a²+b²+c² = 81-46

= a²+b²+c² = 35 Ans