Linear Functions

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

• y = 150 + 40
• y = 40x + 150
• y = 150x + 40

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

Which equation shows the number of bottles left after x days?
A family buys a case of water with 48 bottles and drinks 5 bottles per day.

• y = 48x + 5
• y = -5 + 48x
• y = -5x - 48
• y = 48 - 5x

Amber's savings account had a balance of $350 rolled over from the previous year. She set it up for $50 to be drafted out of her checking account and into her savings account every month. What information in this problem represents the y-intercept?

• 350
• 50
• -50
• -350

Sandra has a $20 itunes gift card and spends $3 each month.  Which equation can be used to find how much money Sandra has on her giftcard after x months?

• y = 3x + 20
• y = 3 + 20x
• y = -3x + 20
• y = -20x + 3

You and your friends plan to attend the county fair this weekend.  Admission to the fair is $5 and the cost per ride is $0.50.  How many rides can you go on if you have $20?

• 20 rides
• 30 rides
• 40 rides
• 50 rides

If I join the gym for a start up fee of $40 and monthly fee of $10,  how much money have I spent if I have gone to the gym for 6 months?

• $60
• $100
• $50
• $110

What is the meaning of the y-intercept?

• The weight in the bucket increases by 1 pound per pound of sand.
• Before sand is put in the bucket, it weighs 1 pound.
• The starting weight of the sand is 1 pound.
• The weight in the bucket decreases by 1 pound per pound of sand.

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

In y=mx+b, which variable represents the y-intercept?

• y
• x
• m
• b