Revision of Depreciation Equipment with a cost of $799,700 has an estimated residual value of $85,700, has an estimated useful life of 30 years, and is depreciated by the straight-line method. a. Determine the amount of the annual depreciation. $ b. Determine the book value after 18 full years of use. $ c. Assuming that at the start of the year 19 the remaining life is estimated to be 19 years and the residual value is estimated to be $80,600, determine the depreciation expense for each of the remaining 19 years. $