Equipment costing $33,600 with a 8-year useful life and an estimated $5,600 salvage value is acquired and started operating on January 1. The equipment is estimated to produce 4,000 units of product during its life. It produced 600 units in the first year. Compute depreciation for the first year under straight-line, units-of-production, and double-declining-balance. Record the journal entries for equipment depreciation for the first year under straight-line, units-of-production, and double-declining-balance.