9. Maintenance records of an excavation machine indicate that the first-year maintenance cost of $800 increases by $300 per year over the 10-year replacement period of the machine. If the maintenance cost is considered to occur at the end of the year and the firm's interest rate is 12%: a) What equal annual payment could the firm make to a service organization to carry out the maintenance for 20 machines? b) How much additional could be paid for a new type of machine with the same service life that required no maintenance during its life