Final answer:
The correct equation to find the regular price per pizza is option c) $48 - $4 = 4p. By solving this, we determine that the regular price of one pizza is $13.
Step-by-step explanation:
The correct equation to determine the regular price of one pizza, p, given that Michelle used a $4 coupon on a $48 order for 4 pizzas, is c) $48 - $4 = 4p. Michelle paid $48 for the pizzas after applying the coupon, so before the coupon, the total cost would have been $48 + $4. To find the price per pizza, we divide the total cost by the number of pizzas, which gives us the equation 4p = $48 + $4 or 4p = $52. To find p, divide both sides by 4, resulting in p = $13, which is the regular price of one pizza.