Can some one help me with my algebra i cant figure this out
A drilling company has a primary unit that can drill at a rate of 7 feet per hour. Because of an equipment failure, the workers must switch to a backup unit, which drills at a rate of 4 feet per hour. They must drill a hole 480 feet deep. Write an equation in standard form describing the process of drilling the hole. Let x represent the hours using the primary unit and y represent the hours using the secondary unit.