I need the written equation.

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?

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.

Find the rate at which the water is now flowing from the tap give your answer cubic centimetres per second