The sales tax where amanda lives is 7%. amanda paid 35$ in sales tax on a new stereo. how much did the stereo cost

Let us assume the cost of the stereo to be = x
Percentage of sales tax paid by Amanda = 7%
Amount of sales tax paid by Amanda = $35
Then
7x/100 = 35
7x = 35 * 100
7x = 3500
x = 3500/7
  = 500 dollars
So the cost of the stereo that Amanda bought was $500. I hope the procedure is clear enough for you to understand. Using this procedure, you can solve similar problems without requiring any help from outside.