Stuck on question and how to solve

Question

9. The Sanchez family had dinner at their favorite restaurant. A 9% sales tax was added to their bill Amy paid the bill with a $10 gift certificate plus $30.60. How much did the family's dinner cost before tax? Round your answer to the nearest penny.

Answer 1

1. Total or the bill: $10.00 + $30.60 = $40.60
2. Sales tax: 9% is changed to 0.09, multiplied by the bill to get the sales tax.
3. a. $40.60 * 0.09 = $3.65
4. Total cost of dinner before the tax: Just subtract part a from part b.