Please answer and explain double-declining balance and units of production.

Acquisition Date Asset Cost Salvage Value Useful Years Units Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 1/2/2021 85,000.00 5,000.00 8 160000 24200 32500 28900 22700 18800 17900 9500 5500 Straight Line Depreciation Depreciable Depreciation Accumulated Cost Expense Depreciation Net Book Value Year 1 2 3 4 5 6 7 8 Double Declining Balance Depreciable Depreciation Depreciation Cost Percentage Expense Accumulated Depreciation Year Net Book Value 1 21 3 4 51 6 7 8 Units of Production Depreciation Rate Per Unit Depreciable Depreciation Accumulated Year Cost Expense Depreciation Net Book Value 1 2 3 41 5 6 7 8