This manual was designed for use with the last of five texts in the Secondary School Advanced Mathematics (SSAM) series. Developed for students who have completed the Secondary School Mathematics (SSM) program and wish to continue their studies in mathematics, this series is designed to review, strengthen, and fill gaps in the material covered in SSM. The subject of the final text is systems of equations, including linear and quadratic equations (and inequalities) in two variables, and linear equations in three variables. Three dimensional coordinate space is developed. This commentary provides mathematical perspective (including the relationship of matrices), a statement of objectives, a suggested time schedule, and answers to exercises. (SD)