In January 2021, EMI Co. purchased a machine that cost $45,000. The equipment is estimated to have a 8-year life (or 40,000 units) and a salvage value of $5,000. (12 points) (a.) Compute the amount of depreciation expense for 2021 using the double declining balance method. $ (b.) Compute the amount of depreciation expense for 2021 using the straight-line method. (c.) Compute the amount of depreciation expense for 2021 using the units-of-activity method assuming 12,000 units were produced in 2021