You have the opportunity to invest in a machine that costs $340,000. The machine generates revenue of $100,000 at the end of each year and requires maintenance costs of $10,000 at the end of each year. The economic life of the machine is five years and the relevant discount rate is 9 perecent.

Add up the following:

Inflow Year 1 x PV Factor for Year 1 @ 9%
Inflow Year 2 x PV Factor for Year 2 @ 9%
Inflow Year 3 x PV Factor for Year 3 @ 9%
Inflow Year 4 x PV Factor for Year 4 @ 9%
Inflow Year 5 x PV Factor for Year 5 @ 9%

Then, deduct the initial investment.

Or, since it's a series of equal payments, just find the present value of an annuity in one step. (same rate, same number of years.)