do not use excel, solve by hand please.

A loan is to be repaid with a series of decreasing annual payments made at the end of each year over a 30 year period. The annual effective rate of the loan is 7.2%. The first payment, made is $12,000, the second payment is S11,700, the third payment is $11.400. the last payment is $3,300. 4.. a. Find the balance after the 9 payment b. Find the balance after the 10th payment. c. Find the amount off principal paid in the 10m payment. d. Find the amount of interest paid in the 10h payment