Paul is looking at two vacation packages while planning a trip to cancun, mexico. in the first vacation package, round-trip airfare costs $799, and it costs $139 per night to stay at the resort. in the second vacation package, it costs $587 per night to stay in the resort and $285 for round-trip airfare. let x represent the number of nights spent at the resort, and let y represent the total cost of the trip. which system of equations could be used to find how many nights paul needs to stay at either resort so that both vacation packages have the same cost? a. b. c. d.