Answer:
Date Account and Explanation Debit$ Credit$
Jan 1 Accumulated depreciation-Machine 63000
 Machine 6300
June 30 Depreciation expense (37000/4)*6/12 4625 
 Accumulated depreciation-Computer 4625 
 (To record Dep)
 
June 30 Cash 6000 
 Accumulated depreciation-Computer 23125
 (37000/4*2.5) 
 Loss on sale of computer 7875 
 Computer 37000 
 (To record sale of computer)
 
Dec 31 Depreciation expense (24500-3400/5) 4220 
 Accumulated depreciation-Delivery truck 4220 
 (To record Dep) 
Dec 31 Cash 9130 
 Accumulated depreciation-Truck 16880
 (24500-3400/5*4) 
 Gain on sale of delivery truck 1510 
 Delivery truck 24500 
 (To record sale of computer)