Answer:
- Car Mart: 11 cars per day
- Winston's: 10 cars per day
Explanation:
Given a graph of cars left at Car Mart after x days with points (2, 43) and (3, 32), and points for Winston's dealership of (3, 32) and (5, 12), you want to know the rate of decrease in cars left for the two dealerships.
Rate of decrease
The rate of decrease is the amount of decrease divided by the time over which it occurs.
Car Mart
The number of cars remaining decreases from 43 on day 2 to 32 on day 3. The amount of change is ...
change = 32 cars -43 cars = -11 cars
The time period is ...
time = (3 days) - (2 days) = 1 day
Then the rate of change is ...
change/time = -11 cars/(1 day) = -11 cars/day
Car Mart sells 11 cars per day.
Winston's
The similar calculations give a rate of change of ...
change/time = (12 cars -32 cars)/(5 days -3 days) = -20 cars/(2 days)
change/time = -10 cars/day
Winston's sells 10 cars per day.