Answer:
straight line method:
depreciation=cost - residual value
number of years
1. D=8000-200 = 7800 = 1560
5. 5
2. D=1600-5000 = 11000 = 2750
4. 4
3.D= 7500-0 = 7500 = 2500
3. 3
4.D 14300-2800 = 11500 = 2300
5. 5
I am not really good at the rest of them but I hope this works