Stan took Lily to his friend's restaurant on a date. The friend told the waiter to remove the $12 dessert from Stan's 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, b. (2 points)

Box( b - Box)= Box

Box( b - 12)= 15