Equations from Problems

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat.  Write an equation for C, the total cost, to rent the boat for h hours.

• h = 2C + 15

• C = 15h + 2

• h = 15C + 2

• C = 2h + 15

Margaret is a waitress at The Seafood Bonanza.  She earns $3 an hour plus 90% of her tips.  Write an equation for her salary, S, if she works h hours and earns d dollars in tips.

• 3h + 0.90d = S

• S = 90d + 3h

• S = 3d + 90h

• S = 3h + 9.0d

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 = 15 + 0.20x

• C =15 (0.20x)

• C = 15 + x + 0.20

• C = 0.20 + 15x

Lisa went to the mall to do her back-to-school shopping.  When she returned, she noticed that the number of shirts (s) she purchased was 3 more than twice the number of pants (p) she bought.  What is an equation that can be used to represent the number of shirts Lisa purchased? 

• p=3 + 2s

• s + 2p =3

• s = 3 + 2p

• 2p = s + 3

Norb is a waiter in a diner.  He earns $4 per hour plus 95% of his tips.  Which equation can be used to determine his salary, S, if he works t hours and earn d dollars in tips?

• S = 4t + 0.95d

• S = 95t + 4d

• S = 0.4t + 9.5d

• S = 4t + 9.5d

A rental company at Best Bargain Rental costs $150 a week, plus $0.10 per mile.  Which equation represents the relationship between the number of miles (x) and the total cost in dollars (y) for a 2- week period?

• y = 2(150)(0.10x)

• y = 2(150) + 0.10x

• y = 150 + 2(0.10x)

• y = 2(150 + 0.10x)

Gracie wants to increase the size of her garden.  If A = lw represents the current area of her garden, what is an equation that can be used to represent the resulting are of Gracie's garden if she increases the length by 5 and doubles the width?

• A = 10lw

• A = 2wl + 10w

• A = 2w (l - 5)

• A = 10wl + 2w

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

• y = 8.50 + 25.50

• y = 8.05 + 25.50x

• y = 25.50 - 8.50x

• y = 25.50 + 8.50x

Daniel is paid $10 per week for selling newspaper subscriptions. He is also paid $3.50 for each new customer(x) that signs up for the subscription. Which equation represents the amount(y) Daniel earns in a week?

• y = 10 + 3.50x

• y = 10 + x

• y = 3.50x

• y = 3.50x

Thomas got a speeding ticket. The officer said he had to pay $10 for each mile(m) per hour he was going over the speed limit plus $115 in court cost. Which equation models the total cost of Thomas' fine?

• c = 125m

• c = 10m + 115

• c = 115m + 10

• c = 10m - 115