Revision of Depreciation Equipment with a cost of $781,200 has an estimated residual value of $83,700, has an estimated useful fe of 45 years, and is depreciated by the straight-line method. a. Determine the amount of the annual depreciation b. Determine the book value after 20 full years of use. C. Assuming that at the start of the year 21 the remaining life is estimated to be 29 years and the residual value is estimated to be $71,000, determine the depreciation expense for each of the remaining 29 years,