plz expain me how to solve this & answer all questions

Problem 1 The Phil-ins Manufacturing Corp. purchased equipment on January 1,2006 for $21,000. The machinery is expected to remain in service for four (4) years and is expected to produce over 1,800 units. At the end of the machines life it is expected to have a residual value of $3,000. It is estimated that the machine will produce 150 units the first year, 350 the second year, 500 the third year and 225 the fourth year. 1) Prepare a schedule of Depreciation reflecting Straight-Line, Units-of Production and Double-Declining Balance. 2) The Depreciation Schedule should be for 2006,2007,2008 and 2009. 3) Which method tracks the wear and tear better? 4) Which method is preferred for Tax-purposes