7.20 Compute the EUAC of the machine of problem 7.15 (7.15 A used machine costs $20000 to purchase. It has annual maintenance cost of $20000, a salvage value of $5000, and a 10 year life. If the interest rate is 10% per year, compounded annually, what is the present-worth of the machine? Answer--- $140,960.12), using the result of problem 7.15. The answer should be $22941.26 per year