Help Delta Machine Company purchased a computerized assembly machine for $135,000 on January 1, 2018. Delta Machine Company estimated that the machine would have a life of four years and a $25,000 salvage value. Delta Machine Company uses the straight- line method to compute depreciation expense. At the beginning of year 3 (2020) Delta discovered that the machine was quickly becoming obsolete and would have little value at the end of its useful life. Consequently, Delta Machine Company revised the estimated salvage to only $5,000. It did not change the estimated useful life of the machine. Compute the depreciation expense for each of the four years. Years Depreciation Expense 2018 2019 2020 S 37.500 2021