finally found it (note by found it I mean I finally found someone with an answer because I couldn't figure it out)
The equation could model a scenario determining the number of players on each team in a league of five teams, if 2 players have to be taken out of the possible players to be referees and to keep score. There will be 11 players on each team.
(I am giving credit to Bre122607 so than they don't delete the answer...)