If x is the amount that Tanya paid for each item, then Tony's items would be x-2.25. So:
3x=4(x-2.25)
3x=4x-9
x=9
x-2.25=6.75
Tanya spent $9 on each item; Tony spent $6.75 on each of his items
<span>books to bookmarks
books : bookmarks
10 : 1
10 * 3 : 1 * 3
30 : 3
3 bookmarks
Since the book store sold 30 books they also sold 3 bookmarks.
Answer: 3 bookmarks</span>
<span>a whole number; a number that is not a fraction.</span>