This document defines and provides examples of key terms in algebraic expressions including variables, coefficients, constants, factors, and algebraic expressions. It explains that variables represent unknown quantities, coefficients are the numbers in front of terms with variables, and constants contain only numbers. Factors are numbers and/or variables being multiplied together. Algebraic expressions contain at least one variable but no equal sign. Word problems can be written as algebraic expressions using words that lead to addition, subtraction, multiplication, or division. Several examples of writing and evaluating algebraic expressions are provided.