Omar and caleb each had a repair made on their cars. the initial cost of each repair is $1,000. omar and caleb each have two coupons. each of them uses both of his coupons toward the cost of the repair. one coupon is for $80 off the repair cost. the other coupon is for 15% off the repair cost. omar and caleb use their coupons in a different order, as shown below.

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?