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 = 5 4 + 5

EvaluatingExpressions• 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) + 120 – 12 + 1

8 + 19

Example 2• Evaluate the following expressions if m = 9, n = 2, and p = 5.

1. 25 – 5p 2. 3. n² + 5n - 6 25 – 5(5) 25 – 25 0

29

82

64

p

m

8)5(2

)9(64

810

544

2

58

(2)² + 5(2) – 6

4 + 10 – 6

14 – 6

8