Linear Functions - Keystone Algebra

Anna's Baker charges a delivery fee of $10.95 for one delivery order of cupcakes. Each cupcake in the order costs $1.15. Which equation describes the relationship between the number of cupcakes ordered (x) and the total cost (y), in dollars, of the deliver order?

• y = 1.15x

• y = 12.10x

• y = 1.15x + 10.95

• y = 10.95x + 1.15

Which set of ordered pairs is a function?

• {(-10, 4), (-8, 3), (-8, 2), (-4, 1)}

• {(-2, 4), (0, 4), (2, 4), (2, 6)}

• {(1, 5), (1, 6), (2, 7), (3, 8)}

• . {(-1, 1), (0, 0), (1, 1), (2, 2)}

A graph of a relation is shown below:
Which statement about the relation is true? 

• The relation is not a function of x because all functions are linear
• The relation is a function of x because values of x increase towards infinity
• The relation is a function of x because each value of y corresponds to one value of x
• The relation is not a function of x because more than one value of y may correspond to the same value of x

The graph below shows the relationship between the number of minutes (x) that have passed since an airplane began its decent and height above the ground (y), in feet, of the airplane.
Based on the graph, how long after it starts its decent will the airplane reach a height of 3,000 feet?

• 14 minutes
• 16 minutes
• 28 minutes 
• 32 minutes

Lee charges $3 for a basket and $2.50 for each pound of fruit picked at the orchard. Write an equation in y = mx + b form for the total cost of x pounds of fruit from the orchard.

• y = 3x + 2.5
• y = 2.50x + 3
• y = 2.50x 
• y = 3x + 2.50

You plan to go snowboarding. The resort charges $15 an hour in addition to $25 to rent a board. Write an equation that represents the cost to go snowboarding for the day.

• y=15x-25
• 15x+25y=100
• 25x+y=15
• y=15x+25

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

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

Which of the following situations could be descried by the equation y= -25x + 120

• There are 120 people in the football stadium, and 25 more are entering each hour.
• A plumber charges $25 for a house call and $120 per hour.
• A teacher has 120 students. Her third period has 25 students
• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

THIS IS QUESTION A.

Sam has $2.50 in his piggy bank. He will add $0.25 each day. How much money will he have in his piggy bank after 12 days?

• $2.50

• $3.00

• $5.50

• $12