Final answer:
The correct expression for the sale price after applying a 15% discount to the regular price, p, is 0.85p, representing the regular price minus 15% off the regular price.
Step-by-step explanation:
If Sarah has a coupon for 15% off any item at the Big Fish Store, and she buys an item at regular price, p, the expression for her sale price is the regular price minus the amount discounted. The discount of 15% off can be represented as a decimal 0.15, so the amount discounted is 0.15 times the regular price, p. To find the sale price, we subtract the discount from the regular price:
Sale price = p - (0.15 × p)
This simplifies to:
Sale price = (1 - 0.15) × p
Sale price = 0.85 × p
Therefore, the correct expression for the sale price is 0.85p, which corresponds to option D.