Answer:
$15
Explanation:
Since we are given the actual equation, which is c = 15d + 24 (it is repeated in the question twice) we can see that the independent variable would be the number of days that the car is rented. Therefore we can simply plug in a value for this to calculate c. So below we can see the total cost for 1 day rent (d = 1 ) and 2 days rented (d = 2)
c = 15(1) + 24 = 39
c = 15(2) + 24 = 54
Now we can simply subtract these two values and to see the daily increase
54-39 = 15
Therefore we can see that the total price will increase by $15 for each day that it is rented.