Which are the solutions of the quadratic equation? x2 = 9x + 6

X^2 = 9x + 6

x^2 - 9x - 6 = 0

use quadratic formula : (-b (+-) sqrt b^2 - 4ac) / (2a)

a = 1, b = - 9, c = - 6

now we sub

x = ( - (-9) (+-) sqrt - 9^2 - 4 (1) (-6)) / 2 (1)

x = 9 (+-) sqrt 81 + 24) / 2

x = 9 (+-) sqrt 105) / 2

x = 9/2 + 1/2 sqrt 105 or x = 9/2 - 1/2 sqrt 105