So on the rental you are reporting income for 3 units and deducting expenses for three units.
When you set it up for depreciation you should have 3/4's of the cost set up.
When you have a general expense (that cannot be allocated to a specific unit) such as trash pickup, you take 75% of the cost as an expense.
When you have a cost that can be directly shown to one unit --such as replacing a toilet in one unit that is a rental, then you deduct 100% of that cost.
Please post a comment if I did not fully address your question.
