i know the answer is 7.51, but need to know how to do it without excel. if you can give a step by step that would be great

4. Given the following information and assuming straight-line depreciation to zero, what is the IRR of this project? Initial investment =$400,000 life =4 years cost savings =$125,000 per year salvage value =$20,000 in year 4 tax rate =34% discount rate =12% A) 6.25% B) 7.51% C) 8.15% D) 9.43% E) 10.24%