1. EXPRESSIONS

2. 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)

3. 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 = 5 4 + 5

4. 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) + 1 20 – 12 + 1 8 + 1 9

5. Example 2 Evaluate the following expressions if m = 9, n = 2, and p = 5. 1. 25 – 5p2. 3. n² + 5n - 6 25 – 5(5) 25 – 25 0 29 (2)² + 5(2) – 6 4 + 10 – 6 14 – 6 8