Final answer:
Matilda will report a combined total net rental income of $5,500 on her tax return, which includes $8,400 of income from Property I and a loss of $2,900 from Property II.
Step-by-step explanation:
The amount of net rental income or loss that will be included in Matilda's personal tax return for the current year is obtained by summing up the net rental income from both properties. For Property I, the net rental income is $8,400, and for Property II, there is a net rental loss of $(2,900). Thus, when combined, the total net rental income that Matilda will report on her tax return is $5,500 ($8,400 - $2,900).