7. New Heights Aviation purchased on January 1, 2020 a plane for $ 500,000. The plane is expected to have a 20 year life after which it can be sold for $ 100,000. Required: a. Compute depreciation expense for first three years using straight line. b. Compute depreciation expense for the first three years using double-diminishing balance method. C. At the end of three years the plane is sold for $400,000. Prepare journal entry to record the sale assuming depreciation was recorded using straight line