Skysong Company purchased a computer system for $75,000 on January 1, 2019. It was depreciated based on a 8 -year life and an $17,400 salvage value. On January 1,2021, Skysong revised these estimates to a total useful life of 4 years and a salvage value of $10,300. Skysong uses straight-line depreciation. Prepare Skysong's entry to record 2021 depreciation expense. (Credit account titles are outomatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter O for the amounts.)