Stan took Lilly to his friends restaurant on a date. The friend told the waiter to remove the 12.00 desser from stand bill. Stan tipped the waiter 20% on the reduced bill. Which was a $15. Tip fill in the blanks to write an equation that will determine the amount of the original bill

Let x be the original bill.

After removing $12.00 from the bill, the reduced amount is x - $12.00.
The tip amount on the reduced bill is (x - $12.00) * 0.20.
The equation that determines the amount of the original bill is: (x - $12.00) * 0.20 = $15.