David wants to start a lawn care business. He offers his clients two different service options: Plan A charges $20 per month plus $5 an hour. Plan B charges $30 per month plus $3 an hour. He used the system of equations below to determine how much money he can make on both plans. y = 5x + 20 y = 3x + 30 If x represents the number of hours he works, and y represents the total money he makes, how many hours would he have to work to make the same amount of money with both plans?