Luca wants to refill a small pond that lost some water through evaporation. The pond has 10 gallons of water in it before Luca uses a hose to fill it up. The pond fills at a rate of 8 gallons per minute. Suppose that y is the amount of water in the pond after x minutes. Which equation could be graphed to help Luca find out how much water is in the pond at any time?