You can depreciate the trailer over five years ... however, you need to adjust that by the proportionate amount of time it's used for business
For example, lets say that you used it for business for 14 days x 12 / 365 = 46%
If your investment in the trailer was %5,000 then you would (if you used it for business 100% of the time) get to depreciate essentially 1000 per year
In this example, you'll use 46% of that (or 460)
I still don't see you coming into the chat here... I can move us to the Q&A mode ... Maybe that will help
Let me know if you have questions at all...
The repairs, license, registration, etc, are for the trailer in general.
Then you just apply that same percentage to get the business deduction