A crack in a water main pipe leaks 7 gallons of water each hour. What volume of water has moved though the crack after 9 hours?

63 gallons of water. y=7h

7=7 (9)

So if we know that 7 gallons of water goes through the pipe every hour, and we want to find how much water goes through the pipe after 9, we want to say,

7 gallons of water 9 times because there are 9 hours.

7 gallons of water 9 times is basically 7 * 9, or 63.

So 63 gallons of water has moved through the crack after 9 hours.