Hi! Your answer will be 8.
Step-by-step explanation (I am not using $ for explaining just to make it easy) :
1. You want to subtract 6 from 85 = 79.
2. Now, he only has $79 to spend on CD's. If each CD costs $9, divide 79/9 and you will get 8.77777777778 which is not a whole number right?
3. This is when rounding comes in, but instead of rounding, we won't have enough to buy 9 so he will just have enough to buy 8 with some money left over.
Hope this helps!! Have a good day :)
