You would need 7 freezer bags because you have to turn both fractions into improper fractions. to get that you have to multiply 15 by 4 and then add 3 so you get 63/1. Then for the next fraction, you multiply 4 by 2 and then add 1 so you get 9/1.
Now you have to divide the 2 fractions to find out how many freezer bags you need. So it would look like this. 63/1 divided by 9/1.
To divide fractions, you use the rule (keep, change, flip)
So you keep the first fraction 63/1 but you change to division sign to multiplication and lastly you flip the second fraction from 9/1 to 1/9 and now you multiply so it looks like this.
63/1 x 1/9 and you get 63/9 which equals 7 freezer bags.
I hope this helped you?? :)