SFU Math 232 Section 2.1. This is the main lecture for section 2.1. This lecture defines a linear system, shows in R^2 and R^3 what the solution sets look like, and details the Gaussian elimination procedure for solving a linear system. You must master Gaussian elimination - we will be using it all the time for a variety of different things. You want to be able to do this quickly and efficiently whenever it is required.