You may want to review quadratic and rational equations first.
Now that you know how to solve quadratic equations, you can solve more kinds of rational equations. Before, you could only solve them if they simplified to a linear equation. Now, though, you can solve things like 2 / x − x = 0. We multiply both sides by x, getting 2 − x2 = 0. This has two solutions, √2 and −√2.
As always with rational equations, we need to check our solutions in the original equation, to make sure we're not dividing by 0. In this case, though, √2 and −√2 both check.