Current value Calculation

Please provide an answer in Excel format. 
6. Assume your firm is zero-growth and pays all its net income in dividends each year Also assume your firm can borrow money when it needs to at an interest rate of 7%. Currently your firm’s cost of equity (Rs) is 10%, but if any money is borrowed that cost will rise to 11%. Sales this year are expected to be $500,000 and operating costs are expected to be $400,000. Your firm’s effective tax rate is 40%. Given these conditions, what is the current value of your firm? What will be the new value of your firm if it takes on $100,000 in debt?
Question 6: $607,273