i try to figure out what is the formula and how to solve these

(Depreciation Computations Five Methods) Jon Seceda Corp. purchased machinery for $315,000 on January 1, 2014. It is estimated that it will have a useful life of 10 years, savage value of $15,000 , production of 240,000 units, and working hours of 2,650 2015 is period hours, and the machinery produces . During 2015, Wenner Corp. uses the machinery for 25,500 units 2 Instructions (c) Working hours (Note Working hours is a "units-of-production" method Cost: Salvage value: Depreciable value Hours of expected life Depreciation per hour: Period hours: Period depreciation (d) Sum-of-years-digits (Note-Utilize Excelformula SYD Cost Salvage Life Period)to solve the problem.) 2015 Depreciation (e) Declining balance, (10 year life) (Note Utilize Excel formula =DDB(Cost, Salvage,Life,Period.Factor) to solve the problem 2015 Depreciation