On March 31, 2018, Marble Trucking purchased a used Kenworth truck at a cost of $55,000. Marble Trucking expects to drive the truck for nine years and to have a residual value of $10,000. Compute Marble Trucking's depreciation expense on the truck for year 1 using the straight-line method. Start by determining the formula needed to calculate straight-line depreciation on the truck through December 31, 2018. = Straight-line depreciation Book value x [(1/ Useful life in miles) x 2] (Months in use / 12 months) [(Cost - Residual value) / Useful life in miles] x Miles driven [(Cost - Residual value) / Useful life in years] x (Months in use / 12 months) (Cost / Useful life in years) x (Months in use / 12 months)