Since A = L * W, W = A / L.
Here, W = (6 1/8 ft^2) / (3 1/2 ft) = 1 3/4 ft.
The garden width is 1 3/4 ft.
I hope you can read my writing and hope this helps
Initial cost = $30,000
Depreciation rate = 2.5%
Depreciation expense per year = 30,000*2.5/100 = $750
In six years,
Depreciation = 6*750 = $4,500
Value of the tractor = Initial cost - Depreciation = $30,000 - $4,500 = $25,500