We frequently work with systems of equations on the coordinate plane. For example, if we are interested in finding the point that represents the intersection of two lines we can solve the corresponding system of equations. Formally, a system of equations is two or more equations that use the same variables. In this section, we will see applications for systems of equations and learn methods for solving systems of equations and inequalities.
You only need to watch up to the end of the first example. You can watch the entire thing if you'd like.
Source: http://patrickjmt.com/
You only need to watch the first example. But also watch the set up for the second example.
Source: http://patrickjmt.com/