Big Valley Ltd, purchased machinery on January 2, 2020, at a total cost of $85,000. The machinery's estimated useful life is 8 years or 60,000 hours, and its residual value is $5,000. During 2020 and 2021, the machinery was used 7,000 and 7,500 hours, respectively. Instructions: Compute depreciation under straight-line, units-of-production, and double-declining-balance methods for 2020 and 2021. 2020 2021 Straight-line depreciation Units-of-production depreciation Double-declining-balance depreciation D oo - Paragraph BI U