At bike shop X it costs $2.25 per hour plus a $4.00 deposit to rent a bike. At bike shop Z it costs $1.25 per hour plus $9.00 deposit to rent a bike. The total cost, c, of renting a bike for n hours at either bike shop can be represented by an equation. Write and solve a system of equations to find how many hours you have to rent the bike for the cost to be the same.