Algebra I is built logically, moving smoothly from one concept to another. Letters are used to represent numbers in expressions and equations. Expressions are simplified and equations are solved. As they work with the axioms, rules and principles of algebra, students are encouraged to use their reasoning ability. Revised 2007. Each complete subject set includes everything you need for one student for one year. Because the set is complete, you are assured that Study Guides, Study Guide Answers, Test and Quizzes, and Test and Quiz Answers are included and are the latest edition available.