Catherine paid $144.97 for an mp3 player. if the price paid includes a 9% sales tax, which of the following equations can be used to determine the price of the mp3 player before tax?

Catherine could take the original price of $144.97 and multiply it by .09 (9%). This would equal a sales tax of $13.073 which could be rounded to $13.01. Then add the original price of $144.97 to the tax of $13.01 to get a total of $157.98.