This document discusses different methods for solving systems of linear equations, including substitution, elimination, and graphing. It provides examples of using substitution and elimination to solve the system 2Y = X + 2, 7X - 12Y = 0. Substitution involves solving one equation for one variable and substituting it into the other, while elimination involves multiplying equations to create common terms that can be eliminated. Graphing involves plotting the lines defined by each equation on a graph and finding their point of intersection.