a theater holds 2,680 seats. the lower level has 100 less than 2 times as many seats as the upper level. the middle level has 80 more than 3 times as many seats as the upper leveel. how many seats are in the middle level?
x + y + z = 2680 x = 2z - 100 y = 3z + 80 x + y = 5z - 20 6z - 20 = 2680 z = 450 y = 1430 Solution: x = 800, y = 1430, z = 450 The middle level has 1430 seats.