Real World Linear Functions

A holiday meal costs $12.50 a person plus a delivery fee of $30.  Which equation represents the amount a holiday meal costs, including delivery, for x people?

• y = 30 + 12.5x 

• y = 12.5 + 30

• y = 12.5 + 30x

The Roaming Cell Phone Company charges $15.00 per month plus $0.20 per minute of airtime usage.  If Juanita uses x minutes of airtime, what is an equation that can be used to determine her monthly cell phone bill (C)?

• C = 0.20x + 15

• C =15 (0.20x)

• C = 15 + x + 0.20

• C = 0.20 + 15x

Easy Car Rental charges $8.50 an hour plus a rental fee of $25.50. Which equation represents the total charges for x hours?

• y = 8.5 + 25.5

• y = 25.5 + 8.5x

• y = 8.5 + 25.5x

Jerry has $20 and makes $7 per hour. Which equation represents the total amount of money Jerry has after working x hours?

• y = 7x + 20

• y = 7 + 20x

• y = 20 + 7

Printer ink costs $16.89 per cartridge. The company that sells the ink cartridges charges a flat rate shipping fee of $4.25, no matter the number of cartridges purchased in a single order. 

 

Which linear function models the total cost, t, for a single order of c cartridges?

• c = 21.14t

• c = 16.89t + 4.25

• t = 21.14c

• t = 16.89c +4.25

Printer ink costs $18.99 per cartridge. The company that sells the ink cartridges charges a flat rate shipping fee of $7.95, no matter the number of cartridges purchased in a single order. Which linear function models the total cost, t, for a single order of c cartridges?

• c = 26.94t

• c = 18.99t + 7.95

• t = 26.94c

• t = 18.99c + 7.95

Printer ink costs $16.89 per cartridge. The company that sells the ink cartridges charges a flat rate shipping fee of $4.25, no matter the number of cartridges purchased in a single order. Which linear function models the total cost, t, for a single order of c cartridges?

• c = 21.14t

• c = 16.89t + 4.25

• t = 21.14c

• t = 16.89c +4.25

A taxi company charges a flat fee of $3 plus $2 per mile driven. Write the function that represents the total cost (C) as a function of the number of miles driven (m). Then, interpret the rate of change and the initial value.

• C(m) = 2m + 3

• C(m) = 3m + 2

• C(m) = 4m + 1

• C(m) = 5m + 2

Sonya has $40 in her lunch account and pays $2 each day to eat lunch.  Which equation can be used to find the amount of money Sonya has left on her account after x days?

• y = 40 + 2x

• y = 40 - 2x

• y = 2 + 40x

• y = 2 - 40x

Veronica earns $15 per hour. She worked 8 hours today. What is her total pay for today?

• $23

• $100

• $120

• $200