can explain how you do an annual excess of fair value amortizations? I do not understand where 21450 and 31920 come from

12 187,500 306,850 Long-term liabilities (mature 12/31/20) Retained earnings, 1/1/17 Supplies Totals 19,600 $851,950 $851,950 During 2017, Abernethy reported net income of $108,500 while declaring and paying dividends of $14,000. During 2018, Abernethy reported net income of $139,750 while declaring and paying dividends of $54,000. Assume that Chapman Company acquired Abernethy's common stock for $711,320 in cash. Assume that the equipment and long-term liabilities had fair values of $411.450 and $155,580, respectively, on the acquisition date. Chapman uses the initial value method to account for its investment Chapman Company obtains 100 percent of Abernethy Company's stock on January 1, 2017 As of that date, Abernethy has the following trial balance: Debit Credit $ 57,600 $ 40,600 50,000 126,000 65,750 Accounts payable Accounts receivable Additional paid-in capital Buildings (net) (4-year remaining life) Cash and short-term investments Common stock Equipment (net) (5-year remaining life) Inventory Land Long-term liabilities (mature 12/31/20) 250,000 390,000 100,000 110,000 187,500