Question

If a + b = 9, ab = 15; find the value of a^2 + b^2

Answer 1

a^2+b^2=51

Explanation given in attached photo, hope it helps you

Answer 2

a + b = 9

ab = 15

(a+b)^2 - 2ab + a^2 + b^2

9x9 - 2x15 = a^2 + b^2

81 - 30 + a^2 + b^2

a^2 + b^2 = 51

:-)