Calculate the depreciation expense with the 4 depreciation methods for a piece of equipment that cost 50,000, with an estimated useful life of 4 years, and a zero-salvage value. What would be the ending book value with the double declining depreciation? The total unit of production are of 100 million and production of units are of 3 millions for year one, 15 millions for year two, 3 millions for year three and 32 millions for year 4. Please put in on charts. Thank you.