Arectangle has dimensions 3x - 1 and x + 6. write an expression for the area of the rectangle as a polynomial in standard form.
a. 3x2 - x-6
b. 6x + 12
c. 8x + 10
d. 3x2 + 17x- 6

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?