Writing and interpreting linear functions

The owner of a small computer repair business has one employee who is paid an hourly rate of $22.  The owner estimates his weekly profit using the function P(x) = 8600 - 22x.  In this function, x represents the number of

• computers repaired per week
• hours worked per week
• customers served per week
• days worked per week

The total cost, c, of leasing a car can be expressed by the equation below where m is the number of months the car is leased. Which statement is true based on the information given?

 $c=1800+185m$  

• The car must be leased for at least 60 months.

• The total cost of leasing this car for 1 year is more than $4000.

• The total cost of leasing this car for 2 years is $4020.

• The cost of leasing this car is greater than the cost of buying one.

Determine the y-intercept from this table.

(a)  

what does "x" represent?

• total cost

• number of cookies

• number of boxes

A fish is swimming at a constant rate toward the ocean floor. The equation y = -7x -3 can be used to represent this situation, where y is the depth of the fish in meters below sea level and x is the number of seconds the fish has been swimming.

Which statement best describes the depth of this fish, given this equation? (7.7A)

• From a starting position of 7 meters below sea level, the fish is descending 3 meters per second

• From a starting position of 7 meters below sea level, the fish is ascending 3 meters per second

• From a starting position of 3 meters below sea level, the fish is descending 7 meters per second

• From a starting position of 3 meters below sea level, the fish is ascending 7 meters per second

Elyse bought a new smartphone. She paid $125 on the day of purchase, then $50 per month until it was paid off. What is the initial value in this situation?

• 50

• 125

• 25

• -75

Jamison is trying out a new diet in order to lose weight. To determine the diet's effectiveness, Jamison keeps a journal where he tracks his weight on a weekly basis. He determines that, in his first two months on the diet, his weight can be modeled by the equation

 $W=-2.5t+195$  
where W is his weight in pounds and t is the time in weeks since he started journaling. Which of the following best describes what the -2.5 means in the context of this situation?

• It is the weight Jamison loses per week.

• It is Jamison's starting weight.

• It is the number of hours Jamison must exercise per week in order to maintain his weight loss.

• It is the amount of time in weeks it takes for him to lose one pound.

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Tags

8.4.C

Here is a graph that shows the amount on Han’s fare card for every day of last July. What is the initial value of the function?

Mathematical Equivalence

ON

Neia is ordering a birthday meal for $12.50 a person plus a delivery fee of $30.  What is b?

• 30

• 12.5

• -12.5