Answer:
total cost of the truck = $100,000 (purchase price) + $8,000 (sales tax) + $400 (registration and delivery fees) = $108,400
residual value = $8,400
depreciation per year = ($108,400 - $8,400) x 1/5 = $20,000
the truck was placed in service in April 1, 2020, 9/12
xx, 2020, purchase of new truck
Dr Truck 108,400
Cr Notes payable 80,000
Cr Cash 28,400
December 31, 2020, depreciation adjustment new truck
Dr Depreciation expense 15,000 (= $20,000 x 9/12)
Cr Accumulated depreciation - truck 15,000