The amphitheater has two types of tickets available, reserved seats and lawn seats. the maximum capacity of the venue is 20,000 people, however, they must sell at least 5,000 tickets for a concert to be held. as an additional constraints, the number of lawn seats cannot exeed the number of reserved seats. if reserved seats profit $65 each and lawn tickets profit $40 each, how many of each must they sell to maximize their profits?