EXPRESSIONS

Vocabulary A variable is a symbol, usually a letter, used to represent a number. –Example: 4x (x is the variable) A coefficient is the number factor of a term that contains a variable. –Example: 4x (4 is the coefficient) A constant is a term without a variable. –Example: 5 A term of an expression is a number, variable, or the product of both. –Example: 4x + 7 (4x is a term, and 7 is a term)

Vocabulary An expression is a mathematical phrase that can contain variables, numbers and/or symbols. –Example: 4x + 7 An algebraic expression is an expression that contains a variable, a number, and at least one operation symbol. –Example: 4 + x When you substitute a number in for a variable, the algebraic expression becomes the numerical expression. –Example: 4 + x, x =

Evaluating Expressions To evaluate an algebraic expression, replace the variable or variables with the known values and then use the order of operations. Example 1: Evaluate the following expression if a=5, b=4, and c=8. 4a – 3b + 1 4(5) – 3(4) –

Example 2 Evaluate the following expressions if m = 9, n = 2, and p = – 5p2. 3. n² + 5n – 5(5) 25 – (2)² + 5(2) – – 6 14 – 6 8