Explain in detail how to compute each of the following depreciation methods: straight-line,units-of-production,and double-declining-balance.

Straight-line depreciation is calculated by subtracting salvage value from the cost of the plant asset and then dividing the result by the useful life.When useful life is measured in years,the resulting amount is the annual depreciation expense for the asset.
Units-of-production depreciation is calculated by subtracting salvage value from the cost of the plant asset and then dividing the result by the useful life in units.The resulting amount is the depreciation expense per unit.That amount is multiplied by the number of units produced during each accounting period to determine the total amount of depreciation expense for that period.
The double-declining-balance method uses twice the straight-line rate (100%/useful life in years)multiplied by the beginning-of-period book value of the asset.The resulting amount is the depreciation expense for that period.