How do you make comparisons between an equation and a verbal description?

y = 1.25x

T-shirts are being sold in a store for $5.25 each.

Equation Verbal

In this lesson you will learn how to compare two functions by analyzing an equation and a

verbal description.

Let’s ReviewLet’s Review

A verbal description is a way to represent a function relation with words.

Input (x) Output (y)

123

246

Mike is selling programs at a baseball game. Each program

costs $2.00.

Let’s ReviewLet’s Review

An equation is an algebraic representation of a function relation.

Input Output

123

246

Output = 2 * Inputor

y = 2x

Let’s ReviewA Common Mistake

Verbal description:

Mike is selling programs at a baseball game. Each program

costs $2.00.

Equation:

y = x + 2

Input (x) Output (y)

123

246

Equation:

y = 2x

Let’s ReviewCore Lesson

=

California offers $0.05 for every soda can brought in to recycle.

Input (x)(cans)

Output (y)(money)

123

0.050.100.15

constant rate of change = 0.05

y = 0.05x

Let’s ReviewCore Lesson

=

Michigan offers $0.10 for every soda can brought in to recycle..

Input (x)(cans)

Output (y)(money)

123

0.100.200.30

Verbal description

Let’s ReviewCore Lesson

y = 0.05x

• Function• One-to-one• Constant rate of

change = 0.05

• Function• One-to-one• Constant rate of

change = 0.10

Michigan offers $0.10 for every soda can

brought in to recycle.

Let’s ReviewCore Lesson

Frank’s mom puts $50 on his lunch card every month. Lunch costs $1.25 per day.

• Function• One-to-one• Constant rate of

change = -1.25

Input (x)(lunch)

Output (y)(money on card)

123

48.7547.5046.25

In this lesson you have learned how to compare functions by analyzing an equation and a

verbal description.

Let’s ReviewGuided Practice

Each honey stick at the county fair costs $0.20. Which equation models the relation of honey sticks (x) to total cost (y)?

A) y = 1.00xB) y = 5.00xC) y = 0.50xD) y = 0.20x

Let’s ReviewExtension Activities

Find an example of a function relation in your everyday activity.

State the input and output and rate of change (if applicable).

Let’s ReviewExtension Activities

Given the following equation, write a possible verbal description for this function relation .

y = 5x + 10

Let’s ReviewQuick Quiz

Harold input $8.00 into a stamp machine and received 20 stamps. If Barbara put in $4.00, how many stamps will she receive?

What is the constant rate of change (cost per stamp)?