Dentify the property used in each step. 12.2 + 18.6 + –4.3 + (–18.6)

12.2 + –4.3 + 18.6 + (–18.6)
12.2 + –4.3 + [18.6 + (–18.6)]
12.2 + –4.3 + (0)
12.2 + –4.3

7.9

Evaluate the expression for the given value of the variable 7a - 4a for a =8

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?

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.