For this case we have a linear function of form:
Where:
y: Represents the total cost of filling and washing
m: Represents the cost of filling the tank of a car with gasoline
x: Represents the capacity of the tank
b: Represents the cost of car washing
To find the slope, we need two points. Be:
Substituting in the formula of the slope, we have:
To find the cost of the car wash, that is, "b", we substitute the slope and any of the points in the equation :
Thus, the cost of a fill-up and a car wash for a customer is: , where x represents the tank capacity of the car to be treated.
If the tank capacity of the truck is 25 gallons, we substitute
Thus, the total cost to fill and wash the truck is 55.75 dollars.
Answer:
Option A