"My pants are at the hotel."
Translation:Minhas calças estão no hotel.
"ficam" shows an activity that lasts longer. So, if you use that this way it could mean, for instance, that he person wears uniform to work but she is can't take it home (the calças are part of the uniform) It would be like "the pants "remain" at the hotel". If you use "estar" it means a moment situation (now my pants are at the hotel)