What is the positive solution of x2 - 36 = 5x?

The equation x^2 - 36 = 5x is a quadratic equation and can be solved thus: x^2 - 36 = 5x x^2 - 5x - 36 = 0 x^2 + 4x - 9x - 36 = 0 x (x + 4) - 9 (x + 4) = 0 (x - 9) (x + 4) = 0 x - 9 = 0 or x + 4 = 0 x = 9 or x = - 4 Therefore, the positive solution of x^2 - 36 = 5x? is 9.