This document introduces algebraic expressions and their components. It defines variables as letters that represent unknown values. Algebraic expressions are formed using variables, numbers, and operations. Coefficients are the numbers multiplied by variables, and terms are numbers, variables, or their combinations using multiplication or division. Constants are numbers that do not change value. The document provides examples of identifying terms, coefficients, and constants in expressions. It also explains how to write algebraic expressions to represent word phrases describing mathematical situations.