please briefly explain/answer 4-6. i will upvote once all answered. thank you in advance.

4. What are the rules for the balance sheet sources and uses of cash? Is an increase in anything on the right side of the balance sheet (i.e., an increase in a liability or equity) a source of cash? 5. Should the ending cash balance shown on a Statement of Cash Flows tie to the cash balance on the Balance Sheet for the same period of time? 6. Fixed expenses are only fixed within the "relevant range" of your forecast. What does this mean? What's an example of a fixed expense