Please provide equations used and explanations

Question: A company's balance sheet for the end of 2019 showed non-cash current assets of $488,000; long-term assets of $985,000; current liabilities of $270,820; long-term liabilities of $421,180; and shareholder equity of $908,000. We also have the following information from the cash flow statement for the year 2020 : cash flows from operating, investing and financing activities were $3,920,($4,700), and $3,008, respectively. Find the: a) working capital at the end of 2019, and b) [net] cash at the end of 2020 . Assume that the company did not have a short-term credit line