revision of depreciation a building with a cost of $360,000 has an estimated residual value of $144,000, has an estimated useful life of 9 years, and is depreciated by the straight-line method. a. what is the amount of the annual depreciation? do not round intermediate calculations. fill in the blank 1 of 1$ b. what is the book value at the end of the fifth year of use? fill in the blank 1 of 1$ c. if at the start of the sixth year it is estimated that the remaining life is 5 years and that the residual value is $100,000, what is the depreciation expense for each of the remaining 5 years? fill in the blank 1 of 1$