Let the number of nosebleed tickets sold = T.....the the number of mezzanine tickets sold = (21500 - T)
So
Number of nosebleed tickets sold * price each + number of mezz tickets sold * price each = revenue
T(20) + ( 21500 - T)(45) = 717500 simplify
20T + 967500 - 45T = 717500
-25T + 967500 = 717500 subtract 967500 from each side
-25T = -250000 divide both sides by -25
T = 10000 = nosebleed tickets sold and 21500 - 10000 = 11500 mezz sold
So.....
Revenue from mezz = 45(11500) = $ 517500
Revenue from nosebleed = 717500 - 517500 = $ 200000
So....they made 517500 - 200000 = $317500 more from mezz sales than nosebleed sales