When we are dealing with more than one linear equation with one unknown, finding a solution is very simple: solve one equation and check if the answer also satisfies the other equation(s). This was what the chapter Linear equations with one unknown was about.

If there are several unknowns, and the equations are linear in all unknowns, solving a system of linear equations is still very doable. That is the subject of this chapter. 

We restrict ourselves mainly to a system of two linear equations with two unknowns and we will develop a so called addition method for solving the system. With a larger number of unknowns the addition method will still work.

We also connect linear equations with two unknowns and lines in the flat plane.

This chapter is a good introduction to the Linear Algebra course. It is also useful, but not necessary, for the Calculus course.