When solving rational equations, you must check your solutions to make sure you are not including extraneous solutions that are not actual solutions to the original equations. If any of the solutions are "excluded values" in the original equation, then they must be thrown out. Using the rational equation,
x + 2 = 10
x - 2 x + 3 x^2 + x - 6
discuss the concepts of excluded values and extraneous solutions. Try to come up with your own examples as well.