Final answer:
Adam's expression represents the sale price after a 75% discount, and Rena's expression represents the sale price after a 25% discount.
Step-by-step explanation:
Adam's expression, d - 0.75d, represents the sale price after a 75% discount. To find the sale price, you subtract 75% of the original price from the original price. For example, if the original price is $100, the sale price would be $100 - 0.75($100) = $25.
Rena's expression, 0.25d, represents the sale price after a 25% discount. To find the sale price, you multiply the original price by 25%. For example, if the original price is $100, the sale price would be 0.25($100) = $25.
So, Adam's expression represents the sale price after a 75% discount, and Rena's expression represents the sale price after a 25% discount.