You may want to review the Quadratic Formula first.
If the equation has other variables, that's okay; you can still solve for one variable using the Quadratic Formula (or any other method, if you can find one that works). The answer will have the other variable in it. For example, suppose you have to solve 3x2 − 4y2 − 2x = 0 for y. You can rewrite this as 4y2 = 3x2 − 2x. The solutions are then −1 ⁄ 2 * √(3x2 − 2x) and 1 ⁄ 2 * √(3x2 − 2x).