i donno ur math background so im not really sure wat ur looking for. im assuming u prolly want to know the total after percentage is applied. example of that will be something like buying 20% off a pair of shoes priced at $50. Then the total T = $50 - (20/100)($50) >>> $50(1 - 20/100). The 20% or 20/100 is applied to the original price $50. Then the price is reduced from the original $50. Or if you want make the problem harder, you can add the tax 8.125% off the sale price. Then it will be T = [$50 - (20/100)($50)][8.125/100] + [$50 - (20/100)($50)] >>> T = [$50 - (20/100)($50)][1 + 8.125/100].
Total = Original - SalePrice + Tax
Given: Original = $50, SalePercentage = 20%, TaxPercentage = 8.125%
SalePrice = SalePercentage x Original = (20/100) x ($50)
Tax = TaxPercentage x Sale Price = (8.125/100) x (20/100) x ($50)
Well lemme know if it helps.