This Instructional Activity is a part of the Lesson 22, Unit 4, Grade 8. A faucet leaks at a constant rate of 7 gallons per hour. Suppose y gallons leak in x hours from 6:00 a.m. Express the situation as a linear equation in two variables. If we say the leak began at 6:00 a.m., and the total number of gallons leaked over the time interval from 6:00 a.m. to x hours is y, then we know the average rate of the leak.