michael just finished a great meal in a restaurant in wisconsin. the sales tax in wisconsin is 5%, percent, and it is customary to leave a tip of 15%, percent for the waiter. the tip amount is calculated on the price of the meal before the tax is applied. sales tax is not calculated on tips.

if michael left $18 on the table to cover his meal, tax, and tip, what was the price of his meal before tax and tip?

Let us assume the total amount of meal charge paid by Michael without tax = x
Then
Amount paid to the waiter by Michael = 15x/100
Sales tax paid by Michael = 5x/100
Now we get the equation as
x + (5x/100) + (15x/100) = 18
(100x + 5x + 15x)/100 = 18
120x/100 = 18
120x = 1800
x = 1800/120
   = 180/12
   = 15 dollars
So the amount paid by Michael for the meal before tax and tip is $15. I hope the procedure is clear enough for you to understand.