You can put this solution on YOUR website!
Since the percentage of the sales tax is not given, we'll just say that it's p, and 0 <= p <= 1 since percentages have to be written in decimal form. It would be $39.50 (which is the cost of the jeans without tax) plus p percent of 39.50. In equation form, that would be
. If we knew the percentage, we can actually figure out the price with tax. Since it wasn't given, we'll have to leave it at