Homework #2.2: Writing Linear Equations

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

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

Bob's Plumbing charges $15 per hour plus a service fee of $40 for coming out to your house. Which equation models this situation?

• y = 15x + 40

• y = 40x + 15

• y = 15x

• y = 15x - 40

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

• y = 12.50 + 30x

• y = 30 + 12.50x

• y = 12.50 + 30

• 12.50x = 30

Eddie's Electric charges $90 per hour plus a $50 traveling fee. Which equation models this scenario?

• y = -50x + 90

• y = 90x + 50

• y = -90 - 50x

• y = 50 - 90x

Amelia has $100 in her savings account and plans on solving $20 per week. Write an equation to represent this situation.

• y = 100x

• y = 20x

• y = 20x + 100

• y = 100x + 20

Joe has $150 in his savings account and saves $40 per month. Which equation represents the amount Joe has in his account after x months?

• y = 150 + 40

• y = 40x + 150

• y = 150x + 40

A plant is 5cm tall and growing at a rate of 3cm a month.

• y = 5 - 3x

• y = 5x + 3

• y = 3x +5

What letter represents the slope of a line in the equation y = mx + b?

• y

• m

• x

• b

What does the "b" stand for in y=mx+b?

• slope

• x-intercept

• y-intercept