Slope and Y-Intercept in Context

Interpret the slope.

• Janice saves $12,000 every 500 months

• Janice saves $500 every 12,000 months

• Each month, Janice saves an additional $500

• Each month, Janice saves an additional $12,000

James has to sell restaurant discount cards as part of a fund raiser for soccer. The equation y = -10x + 500 models his selling where y is the total number of cards and x is the number of days.

Interpret the slope.

• James is selling 500 cards over 10 days

• James earns $500 for every 10 cards he sells

• James is selling 10 cards each day

• James starts with 500 cards to sell.

James has to sell restaurant discount cards as part of a fund raiser for soccer. The equation y = -10x + 500 models his selling where y is the total number of cards and x is the number of days.

Interpret the y-intercept.

• James is selling 500 cards over 10 days

• James earns $500 for every 10 cards he sells

• James is selling 10 cards each day

• James starts with 500 cards to sell.

Chris collects shoes. The equation y =3x + 122 models the number of pairs of Jordans(y) he has in his collection after x months.

Interpret the slope.

• Chris collects an additional 3 pair of Jordans each month

• Chris collects 122 pairs of Jordans every 122 months

• In 3 months, Chris will have 122 more pairs of Jordans.

• Chris sells 3 pairs of Jordans for $122 each.

• The y-intercept is $850/car and it represents the commission per car sold.

• The y-intercept is $1500/car and it represents the commission per car sold.

• The y-intercept is $1500 and it represents the monthly salary before commission.

• The y-intercept is $2775 and it represents the monthly salary before commission.

• The slope is $850/car and it represents the commission per car sold.

• The slope is $425/car and it represents the commission per car sold.

• The slope is $1500 and it represents the monthly salary before commission.

• The slope is $850 and it represents the monthly salary before commission.

Which of the following situations could be descried by the equation y= -25x + 120

• There are 120 people in the football stadium, and 25 more are entering each hour.

• A plumber charges $25 for a house call and $120 per hour.

• A teacher has 120 students. Her third period has 25 students

• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

What does the slope represent in this situation?

• The sloth runs 1 feet in 3 minutes

• The sloth runs 3 feet in 1 minute

• The sloth runs fast

• The sloth runs 6 feet in 1 minute

The graph represents gasoline consumption when driving a certain distance in km.  What is the meaning of the slope?

• The tank started with 50 L of gasoline

• the amount of gasoline consumed per km driven

• the distance it takes to lose a Liter of gas

• the gasoline is leaking because the slope is negative.

What is the correct equation in 
Slope-Intercept Form?
(y = mx +b)

• y = 1/3x - 1

• y = 1/4x -1

• y = -1/3x +1

• y = -1/4x + 1