Answer:
x (upper level) = 12,000 tickets
Explanation:
Firstly, let's convert this gibberish text into the information we want. :D
Total amount of people = 52,000
Main floor tickets = $25 each
Total: $1,144,000
Let the amount of people who brought upper level tickets be x and main floor tickets be y. (assumming 1 ticket = 1 person)
Thus, we come up with this simultaneous equation:

The first equation finds the price of the ticket, while the second is the amount of people.
x (upper level) = 12,000
y = 40,000
Hope this helps! :)