Skylar needs to buy a pair of dress pants for $40, a shirt for $30, and a tie for $20. skylar has three coupons. the first coupon gives him x percent off on a shirt. the second coupon gives him y percent off on the dress pants. the third coupon gives him z percent off on his total purchase. he cannot combine the coupon for the total purchase with the other two coupons. these expressions give both possibilities for the total cost of skylar's purchase after the coupons are applied. the variables represent percentages as decimals. (1−x)30+(1−y)40+20 (1−z)(40+30+20) skylar uses the dress pants coupon. which part of the expression represents the percent that skylar will pay for the dress pants?