The amount of water, , in gallons, in a swimming pool after hours of filling is modeled by the equation . What does the number 500 represent in this equation?
The rate at which water is being added to the pool, in gallons per hour.
The total amount of water in the pool after 150 hours.
The initial amount of water in the pool before filling began, in gallons.
The maximum capacity of the swimming pool, in gallons.
