Given the popularity of IRR, Casey has decided to use it to evaluate a project. The cashflows from the project will be $40k, $42k and $28k in years 1 through 3. After that the project will have cashflows of $20k per year, forever. The projects initial cost is $450k and the opportunity cost/hurdle rate is 7%. Write down the equation used to solve for the IRR (do not solve for the actual IRR)