Can you show formulas and how thw answer was discovered? Thank you!

1. Assume a new tractor is purchased on January 1 for $124,000 with a salvage value of $20,000 and a useful life of 8 years. What would the annual depreciation be for the first two years under each depreciation method? Year 1 Year 2 Straight line Double declining balanc Straight line: Annual depreciation for year 1- Annual depreciation for year 2- Double declining method: Annual depreciation for year 1 = Annual depreciation for year 2- 2. For the problem above, what would the tractor's book value be at the end of year 2 under each depreciation method? Book value under the straight-line method Book value under the double declining balance method