Challenge A customer at a clothing store is buying a pair of pants and a shirt. The store is having a 15%-off sale on all pants. The customer has a coupon for 10% off entire purchase. The coupon cannot be combined with any other offers, so can choose only one option. Let n represent the original price of the pants and s represent the price of the shirt. Write two equivalent expressions for each option. If the original cost of the pants is $ and the shirt is $, which option should the customer choose? Which two expressions represent the 15"%-off sale on all pants" option?