Hi everyone, I have a little question:
To prepare the adjusting entry at year end of "Rent paid in advance, 4,500 $"
I have to Dr. Rent expense and Cr. Prepaid rent.
But what if the exercise says "Rent paid in advance, 4,500 $ (originally charged to expense)"? what does this "originally charged to expense mean and how should I proceed now with the adjusting entry? Thank you

Rent paid in advance is a prepaid asset. The original journal entry should have been a Debit to Prepaid Rent and a Credit to Cash.

So you have to correct the journal entry that was incorrectly recorded, or move the amount of Prepaid in advance that has not been expensed yet.