Start by calculating the price of the machinery. It is $96,000 - $9,600 + $600 + $4,500 = $91,500. To figure the annual depreciation, we subtract the residual value of $30,000 to yield a cost of $61,500. Since the machinery has a useful life of 10 years, annual depreciation using the straight-line method is $61,500/10, or $6,150.