You are trying to buy gasoline for your truck before a road trip using the one-hundred dollars ($100) cash you have available. You use all of your money and you purchase 25 gallons of gasoline. Later on in the trip, after acquiring more cash, you must buy gasoline again and you buy the gasoline at the same rate of cost. You plan to purchase "I" gallons of gasoline. Which of the following expressions will tell you how much money (in dollars) it will cost you to purchase a gallons of gasoline?