A definition of a line is given, along with the requirements to completely specify one. Slope is defined and its four types are graphically and analytically shown. Parallel and perpendicular lines and their determination by slope are described. Various formulas to write equations of lines are discussed. Systems of linear equations are covered along with methods of solving them. Criteria are given to determine if there is a solution of a system, and if so, how many. Finally, 56 graduated problems are given for students to solve along with their detailed solutions.