This video teaches you how to use substitution to find the point on a graph (the x and y coordinates) where two separate equations would cross. Substitution is a trick of algebra that allows you to find this point without making a graph. The first step is to isolate one of the variables (x or y) in one of the equations. That way, you know that that variable is equal to everything on the other side of the equals sign from it. You can then take that whole side, and substitute it into the other equation where the variable you isolated originally was. Using this method you can isolate the other variable, and solve for it. Then you can use substitution for the other variable, plugging in the answer you already found and solve for the other one. Voila! Now you know both x and y coordinates and you have your answer. If you follow the steps in this video you will soon understand how to use substitution to solve math problems!