Suppose we want to solve an equation such as x^3 + 2x^2 -3x + 6 = 0. We can use the rational root theorem to find the possible rational roots and then use synthetic division to find a root. After we find a root, we will have a quadratic equation left to solve to obtain the other roots. This can be quite tedious. With a graphing calculator, you can solve this equation by seeing where the graph of the equation crosses the x-axis. These points are the solutions to the equation. If you have multiple equations, the solutions are the intersection points of the graphs.