Answer
23 CDs
Work Step by Step
In order to solve this, we need to name c as the variable which represents the number of current CDs. Since we know that the total amount that the rack can hold is 30 CDs, and we can add 7 more CDs before it is full, our equation would look like:
c+7=30
Then, we need to get c by itself, so we subtract 7 from each side.
(c+7) -7 =30 -7
c=23 CDs
