He can claim $5,000 off the top as a current deduction.
The remaining $4,000 must be amortized over the 180-month period, which is a monthly amount of $22.22. Her amortization deduction for the first year would be $177.78 ($22.22 for each of the 8 months he was in business in 2016.)
This amount $177.78 would be reported on Form 4562 for the first year and carried over to his Schedule C.