P7-3 Depreciation by two methods; partial years Knife Edge Company purchased tool sharpening equipment on July 1, 20Y5, for $16,200. The equipment was expected to have a useful life of three years and a residual value of $900. Instructions Determine the amount of depreciation expense for the years ended December 31, 20Y5, 20Y6, 20Y7, and 20Y8, by (a) the straight-line method and (b) the double-declining-balance method