2. Vanessa wants to model how a car's maintenance costs change as the distance someone drives the car increases. What would be an appropriate unit for Vanessa's purpose?
If Vanessa wants to know hoy the car's maintenance costs change as the distance increases, she is analysing the cost of maintaining the car (wich is expressed in dollars , $), when the distance increases (which is measured in miles or metres, or some other distance measure).
Then, the appropiate units of measure for this problem are dollars (to represent the cost of maintenance) and miles (to represent the distance the car travels).