Can you please explain this?

13 The December 31, 2004 Balance Sheet of Cool Company shows Assets of $35,000 and Liabilities of $23,000. During the year 2005, the company issued additional stock for $3,500, and paid dividends of $800. If the December 31,2005 Balance Sheet shows Assets of $43,000, and Liabilities of $27,000, and the Income Statement shows Revenues o $80,000,how much were Expenses? 781700