2. Double-declining balance Depreciation Year Expense 2015 $ 2016 2017 2018 2019 Units of Production Depreciation Year Expense 2015 $ 2016 2017 2018 b. Assume that the machine was purchased on July 1, 2015. Calculate each year's depreciation expense for the machine's useful life under each of the following depreciation methods 1. Straight-line. 2. Double-declining balance. 1. Straight-Line Depreciation Year Expense 2015 $ 0 2016 2017 2018 2019