Water flows back and forth between a small and large tank. When water is moving into a tank the flow rate is positive, and when water is moving from a tank the flow rate is negative. The large tank begins with 300 gallons of water, and the small tank begins with 200 gallons of water. After a period of 5 minutes, the large tank has the same amount of water as the small tank. Which statement describes the flow rate? HELP??!?!