I can give you variables to show the tax and price.
price = p
tax=t
c=cost
[tex]( \frac{t}{100} \times p ) + p = c [/tex]
You have to put the tax back in the initial form, so you divide by 100. You then want to find the percentage of the price of the item by multiplying it. You add it on to the tax because you can't just pay the tax and not pay for the item, you have to pay for both.
Tell me if this helps!!
