Catherine paid $155.87 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 player before tax? How much was the MP3 player before tax?
a) y = 1.09x
$143.00
b) y = 1.09x
$166.90
c) y = 1.9x
$166.90
d) y = 1.9x
$143.00