How to Net income or net loss when there are given assets, liabilities, no additional investment as well as withdrawals?

How to Net income or net loss when there are given assets, liabilities, no additional investment as well as withdrawals?

Example: Net income (or net loss) during 2019, assuming that as of December 31, 2019, assets were $880,000, liabilities were $220,000, and there were no additional investments or withdrawals.