If you have a system of two linear equations, you can solve it by graphing. Here are the steps.
1. Solve both equations for y to put them into slope-intercept form.
2. Graph both equations on the same plane.
3. Find the point where the lines intersect. This is the solution to the system of equations.
For a system of two linear equations, the lines could intersect once, at one point, for one solution; infinitely many times, if they are the same line, for infinitely many solutions (all real numbers); or not at all, if they are parallel lines, for no solution. Be aware of those possibilities.
Here is a video explaining how to solve a system of linear equations by graphing.