Someone pays your $8000 for a 2-year structured settlement of $5000 each year for the next year and the year after that.
So each cash flow would be
(each is 1 year)
CF 0 = $8000
CF 1 = -$5000 (negative because you don't get it)
CF 2 = -$5000 (negative as well because you don't get it)
How do you solve for an implicit interest rate without using a finance calculator and solving for an IRR