Sure, let's break this problem down step by step to determine how much money each book cost.
1. Identify the initial amount of money Joan had:
- Joan initially had [tex]$279.
2. Determine the amount of money left after buying the books:
- After making her purchases, Joan had $[/tex]18 remaining.
3. Calculate the total amount of money spent on the books:
- To find out how much she spent, subtract the money she had left from the money she started with:
[tex]\[
\text{Money spent} = \$279 - \$18 = \$261
\][/tex]
4. Find out the number of books Joan bought:
- Joan bought 9 books in total.
5. Calculate the cost per book:
- To find the cost of each book, divide the total amount of money spent by the number of books purchased:
[tex]\[
\text{Cost per book} = \frac{\$261}{9} = \$29.00
\][/tex]
So, each book cost $29.00.
