Your family has a car with a 15 gallon gas tank. Find the price of 1 gallon of gas in your area. Then write and solve a division equation to find the price P to fill the cars gas tank when it is empty. Perio your family has a car with a 15 gallon gas tank. Find the price of 1 gallon of gas in your area. Then write and solve a division equation to find the price P to fill the cars gas tank when it is empty.