A tractor for over-the-road hauling is purchased for $80,000.00. It is expected to be of use to the company for 6 years, after which it will be salvaged for $4,400.00. Calculate the depreciation deduction and the unrecovered investment during each year of the tractors life. a. Use straight-line depreciation. Provide depreciation and book value for year 6. Depreciation for year 6=$ book value for year 6=$ b. Use declining-balance depreciation, with a rate that ensures the book value equals the salvage value. Provide depreciation and book value for year 6 . Depreciation for year 6=$ book value for year 6=$ c. Use double declining balance depreciation. Provide depreciation and book value for year 6. Depreciation for year 6=$ book value for year 6=$ d. Use double declining balance, switching to straight-line depreciation. Provide depreciation and book value for year 6. Depreciation for year 6=$ book value for year 6=$