Expressions: Substitution and simplifying algebraic expressions Quiz

The ability to simplify algebraic expressions is frequently tested on the SAT. To do so, you might need to combine like terms or find common factors. You might also need to use substitution to solve a problem. This often involves getting one unknown value (such as x) in terms of another (such as y). For example, once you know that x = 3y, then the term 3y can be substituted for x in any expression since they are exactly the same. In all cases, you should apply the rules of arithmetic to the unknown terms just as you would to known values.