As far from I know, you can use the quadratic formula or factor this equation. It's easier to factor instead because this is efficient to certain types of quadratic equation. In order to factor the equation, suppose you draw an big X. Each part of the 'X' is very substantial to help solve the equation. On the top, multiply the coefficient from '9x2', in which 9 is your coefficient, and multiply it with the last number, -2. Your total is -18. With the 3x left on the equation, place the 3 on the bottom of the 'X' mark. Now, you need to find two numbers that multiply and add/subtract to -18 and 3. The only two possible numbers are 6 and -3. However, those are not your final answers because they're not an restriction to 0. You will get (x+6)(x-3). Finally, find the opposite of both of the two separate equations and you will find your final answers.