The cost that a carpet cleaning company charges is directly proportional to the number of rooms cleaned. the cost is $22 for each room.

(a) write a direct variation equation to represent the cost.
(b) how many rooms can a hotel pay the company to clean for $200? write and solve an equation.
(c) suppose the hotel plans to tip the carpet cleaners $40, how many rooms can the hotel get cleaned for $200 now? write and solve an equation.