Please thoroughly explain and show work to answers. I'm so confused.

In 2022, Firm L purchased machinery costing $21,300 and elected to expense the entire cost under Section 179. Required: a. How much of the expense can Firm L deduct if its taxable income before the deduction was $58,000. b. How much of the expense can Firm L deduct if its taxable income before the deduction was $19,200. c. How much of the expense can Firm L deduct if its net operating loss ( NOL ) before the deduction was $5,016