can someone please explain how to do this. im not really sure where to start. if someone could explain this in detail that would be great thank you.

On January 1, Pacific Specialty Foods purchased equipment for $21,000. Residual value at the end of an estimated four-year service life is expected to be $2,100. The machine operated for 2,200 hours in the first year, and the company expects the machine to operate for a total of 10,000 hours. Calculate depreciation expense for the first year using each of the following depreciation methods: (1) straight-line, (2) double-declining-balance, and (3) activity-based. (Do not round your intermediate calculations.)