E9-5 Gotham Company purchased a new machine on October 1,2017 , at a cost of $90,000. The company estimated that the machine has a salvage value of $8,000. The machine is expected to be used for 70,000 working hours during its 8 -year life. Instructions Compute the depreciation expense under the straight-line method for 2017 and 2018 , assuming a December 31 year-end