III. Depreciation Expense Hart Company purchased machinery for $650,000 on January 1, 2020. The company estimated that the machine would have a salvage value of $50,000 at the end of its service life. It's life is estimated at 5 years. Instructions: Compute the depreciation expense for 2020 and 2021 under the following methods. Each of the following should be considered unrelated. (a) Straight-line. (b) Sum-of-the-years'-digits. (c) Double-declining balance