If anyone can help me with this it would be awesome

What is the equation of the linear function represented by the table?

How do you solve a question like this?

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?