Final answer:
The annual depreciation for the first two years using each method is $10,000.
Step-by-step explanation:
To calculate the annual depreciation for the first two years using each of the given methods, we need to first calculate the annual depreciation expense.
We can use the formula:
Annual depreciation expense = (Initial cost - Residual value) / Service life
For the first year:
Annual depreciation expense = ($90,000 - $30,000) / 6
= $10,000
For the second year:
Annual depreciation expense = ($90,000 - $30,000) / 6
= $10,000
So, the annual depreciation for the first two years using each method is $10,000.