On january 1, 2019, the harold company purchased equipment at a cost of $400,000. the equipment was expected to have a service life of 10 years and a $20,000 residual value. the company’s fiscal year-end is december 31, and the double-declining balance (ddb) depreciation method is used. at the beginning of 2021, the company switched from the ddb to the straight-line method. in 2021, the adjusting entry to depreciation expense is: