How do I find what is the Delta IRR of the difference between the cashflow of the machinewith the higher initial value and the lower initial value withthe following data? 

Benefits are constant over all years.

Initial cost Machine A Machine B $125,000 $175,000 Life in years 3 6 Salvage after life 15% 15% Benefits per year $72,000 $81,000 Costs per year $15,800 $24,200 Inflation 2.50% Costs keep increasing at 2.5% every year even when a new machine is bought.