Betty bought two bags full of books at an annual library book sale. If she

pays a total of $12.90 for both bags, of which $0.90 is tax, how much did

each bag of books cost?

12.90=.90 + 2x

12=2x

6=x

Each bag of books cost was $6

Answer: the answer is $6

Step-by-step explanation:

Since Betty payed. 90 cents on tax we can subtract this from the equation because we are just trying to focus on how much she spent on one bag. Now all we have left is $12. Then we would have to divide 12 by the number of bags she bought, so 2. 12 divided 2 equals 6, meaning Betty spent $6 per bag.