9. Because you have to find out how much each bag costs so you divide the total cost by the ammount of bags. When you do this you get $5 dollars a bag for the 5 bags and $6 dollars a bag for the 7 bags.
10. You need to find out how much each book cost so you divide the amount of money by 6 and you get $2.09. Then you multiple 8 by 2.09 and you get 1672 but then you have to move the decimal to the left two times and you end up with $16.72.
