Linear Equations

A plumber charges a flat fee for each job, plus an hourly rate for the number of hours the job takes to complete. The cost of the job, in dollars, can be modeled by the expression y = 65x + 50. What is the y-intercept in the expression represent in this situation and what does it represent.

• the number of jobs, x

• the cost per hour, $65

• the cost per hour, $50

• the flat fee, 50

• the total cost of the job, y

A plumber charges a flat fee for each job, plus an hourly rate for the number of hours the job takes to complete. The cost of the job, in dollars, can be modeled by the expression y = 65x + 50. What is the rate of change (slope) in the expression and what does it represent in this situation.

• the flat fee, $65

• the number of hours to complete the job, x

• the cost per hour, $65

• the flat fee, $50

• the total cost of the job, y

What is the slope of the following graph?

• m = 80

• m = 20

• m = 40

• m = 160

The graph shows the amount of gas a tractor uses given the number of miles traveled. What does the slope tell you?

• 1/20 of a gallon of gas in increased every mile driven.

• 1/20 of a gallon of gas is used every mile driven.

• 4 gallons of gas is increased every mile drive.

• 5 gallons of gas is used every mile driven.

The graph shows the amount of gas a tractor uses given the number of miles traveled. What does the y-intercept tell us?

• That the tractor traveled 40 miles.

• How much gas the tractor started with.

• After 60 miles the tractor had 1 gallon of gas.

• 1/20 of a gallon of gas is used every mile.

The graph shows the cost of candy as a function of the weight of the candy. Calculate the slope.

• $2.66 for every ounce of candy bought

• $3 for every ounce of candy bought

• $0.50 for every ounce of candy bought

• $0.38 for every ounce of candy bought

The table shows the cost of a taxi, given the number of miles traveled. Calculate the slope and explain the meaning.

• The taxi charges $0.30 for every mile traveled.

• The taxi charges $1.00 for every mile traveled.

• The taxi charges $1.30 for every mile traveled.

• The taxi charges $2.50 for every mile traveled.

The table shows the amount of water in a pool as it drains. Calculate the slope and explain what it means.

• 2.4 gallons of water are added to the pool each hour.

• 2.4 gallons of water are drained from the pool each hour.

• 41 gallons of water are added to the pool each hour.

• 41 gallons of water are drained from the pool each hour.

The graph shows the height of a candle after the given number of minutes. Calculate the slope and state its meaning.

• The candle decreases in height by 1/10 of an inch every minute.

• The candle increases in height by 1/10 of an inch every minute.

• The candle decreases in height by 1/2 of an inch every minute.

• The candle increases in height by 1/2 of an inch every minute.

A truck rental company charges $19.95 to rent a truck plus $0.24 per mile driven.

Which equation models the problem?