5. Depreciation. Matt Brown, a farmer, just purchased a new farm tractor for $80,000. At the end of expected economic life (7 years) of this tractor, it will have a salvage value of 10 percent of its original purchased price. Use four (4) methods of depreciation discussed in class to calculate depreciation for each of the years of economic life. Show all formulas, calculations and results below. Straight line Sum of the years digits Declining balance MACRS