ABC PURCHASED AN ASSET ON JANUARY 1, 2016 FOR 50,000.THE ESTIMATED USEFUL LIFE OF THE ASSET IS 4 YEARS, 45,000 MILES OF TOTAL USE. THE ESTIMATED SALVAGE VALUE IS 5,000. CVALCULATE DEPRECIATION EXPENSE PER YEAR UNDER I-STRIGHT LINE METHOD 2-UNITS OF PRODUCTION METHOD 3-SUM OF THE YEARS DIGITS METHOD . 4-DOUBLE DECLINING BALANCE METHOD