$6.$ Forman, Inc. owns machinery with a cost of $$250,000.$ Its estimated useful life is $10$ years and a $$30,000$ salvage value.

Determine the depreciation expense for each of the $10$ years of the asset$$s life, assuming the company uses:

a$.$ Straight$-$line method

b$.$ Double$-$Declining Balance method

c$.$ Sum of Year$$s Digits method