Deon is riding his bicycle. he rides for 7 hours at a speed of 22.4 kilometers per hour. for how many kilometers does he ride

The total cost of anja’s trip to the dentist was $628.35. she paid a flat fee of $89.95 which included the checkup and cleaning and then had 4 cavities filled, each of which cost the same amount. which shows the correct equation and value of x, the cost of each cavity filling?