Answer:
$25
Step-by-step explanation:
Derive an equation to represent the cost of using each ride.
Sal's Car Rides:
Using 2 pairs of values from the table, (0, 40) and (20, 80), find the slope, m (fee per mile).

The y-intercept, b, is the one-time fee for fuel. This is the value of the cost ($) when number of miles traveled is 0.
Thus, b = 40.
Substitute m = 2, and b = 40 into
.
Equation for the total cost for Sal's Car Rides would be:
.
Find the total cost to be charged if a customer requires the a car service for 80 miles if he chooses Sal's Car Rides.
Simply substitute x = 80 in
.

The customer would pay $200.
Ray's Limo:
The equation that represents the total cost (y) to be charged for number of miles (x), given that $2.50 is charged per mile plus a one-time fee of $25 for fuel, would be:
.
If a customer uses Ray's Limo services for 80 miles, the cost charged would be:
Substitute x = 80 in
.
Thus:
.
The fee the customer would pay = $225 for using Ray's Limo services.
Therefore, if the customer takes Sal's Car Rides instead of Ray's Limo, he would save, $225 - $200 = $25.
The customer would save $25.