18.In January 2007, installation costs of $8,000 on new machinery were charged to Repair Expense. Other costs of this machinery of $30,000 were correctly recorded and have been depreciated using the straight-line method with an estimated life of 10 years and no salvage value. At December 31, 2008, it is decided that the machinery has a remaining useful life of 20 years, starting with January 1, 2008. What entry(ies) should be made in 2008 to correctly record transactions related to machinery, assuming the machinery has no salvage value? The books have not been closed for 2008 and depreciation expense has not yet been recorded for 2008.? Please answer question 18 from Ch 22. What did you find to be the most challenging part of the problem? Explain why?