Systems of Linear Equations

A system of linear equations is a composed of two or more equations with the same variables.

If you have two variables then you need two equations
three variables - three equations, and so on.

Let say you have a system of two equations, if you were to graph the two equations
we would say the system has a solution where the two lines intersect.
If the two lines run parallel then there are no solutions.
If the two lines coincide, then they are the same, and there is an infinite number of solutions.