If you would like to solve (x^2 + 5x - 36) / (x + 9), you can do this using the following steps:
a = ?
(x + 9) * (x + a) = (x^2 + 5x - 36)
x^2 + ax + 9x + 9a = x^2 + 5x - 36
ax + 9x = 5x
a + 9 = 5
a = 5 - 9
a = - 4
The correct result would be c. x - 4.
