the black limo company (blc) purchased a limo on january 1 of year 1. the limo cost $48,000. it had an expected useful life of 4 years and a $8,000 salvage value. blc uses the straight-line depreciation method. at the beginning of year 3, blc changed the estimated useful life from 4 years to 7 years. based on this information, the amount of depreciation expense shown on the year 3 income statement will be: