Answer:
3 months.
Step-by-step explanation:
Let x represent the number of months.
We have been given that Tom has a collection of 30 CDs and he is adding 1 CD a month to his collection.
So number of CDs in Tom's collection after x months would be: .
We are also told that Nita has a collection of 18 CDs. Nita is adding 5 CDs a month to her collection. So number of CDs in Nita's collection after x months would be: .
To solve for number of months, when both will have same number of CDs, we will equate both expressions as:
Therefore, after 3 months they will have the same number of CDs.