3.1 Algebraic Expressions
1. An Algebraic Expression may contain 1 or more variables, numbers,
and operation symbols. EX. 2x + 4
Parts of an algebraic expression are called terms.
2. A variable is a letter or symbol that represents a quantity that can
change. EX. x
A coefficient is the numerical factor of a term that contains a variable.
EX. 2x
3. A constant is a quantity that does not change. EX. 4
4. To evaluate means to find a value or “answer”. To evaluate an
algebraic expression, substitute a value for the variable, then perform
the operation.
EX . 1. Evaluate x ÷ 6 when x = 6
EX. 2. Evaluate a ÷ b when a = 16 and b =
2
3
EX. 3. Evaluate 3x – 14 when x = 5
Real-Life Application
You are saving money to buy a skateboard. You begin with $45, and
you save $3 each week. Write an expression to solve.
Can you buy the skateboard after 20 weeks?