1.1 Algebraic Expressions & Formulas

Review Vocabulary

ӕ A variable is a ______________________________________________________________________

____________________________________________________________________________________ .

ӕ An expression that contains one or more variable is an _________________________________ .

ӕ Could we call these equations? Why or why not? _______________________________________

____________________________________________________________________________________ .

Simplifying

ӕ To simplify an expression is to _______________________________________________________ .

How do we know where to start? _____________________________________________________ .

Examples: Simplify each expression.

a) b) c)

Evaluating

ӕ To evaluate an expression is to _______________________________________________________ .

How do we know where to start? _____________________________________________________ .

Examples: Evaluate each algebraic expression for .

a) b) c)

Formulas

Example: The expression models the percent of eligible voters who voted in presidential elections for 1960 to 2000. In the expression, y represents the number of years since 1960. Find the approximate percent of eligible voters who voted in 1988.

Example: Suppose you are about a mile from a fireworks display. You count 5 seconds between seeing the light and hearing the sound of the firework, and estimate the viewing angle created by your line of sight looking to each end of the firework to be about 4 degrees. To estimate the width w in feet of the firework burst, use the formula w = 20At. In this formula, A is the estimated viewing angle of the firework display and t is the time in seconds from the instant you see the light until you hear the sound. Estimate the width of the firework.