5. Kellman Company purchased a machine on January 1, 2009 for $200,000. The company estimated that the machine will have a useful life of 10 years, and a salvage value of $20,000. On January 1, 2014, the company determined that the machine would have a remaining useful life of 4 years, and a salvage value of $10,000. Assuming the company uses straight-line depreciation, determine the revised depreciation expense for the year ended on December 31, 2014.

the asnwer is 25000 but i need the solution that how i can get that number?