Equipment with a cost of $711,900 has an estimated residual value of $81,900, has an estimated useful life of 35 years, and is depreciated by the stralght-line method. a. Determine the amount of the annual depreciation. b. Determine the book value after 17 full years of use. c. Assuming that at the start of the year 18 the remaining Ife is estimated to be 23 years and the residual value is estimated to be 567,800 , determine the depreciation exbense for each of the remaining 23 years