Series Applications

[frog0101]

Hi, I have 2 questions that I am unable to solve from the Excel 3 Unit book, any help would be greatly appreciated:
(1) In return for the bank lending you money to buy an automobile, you sign a contract agreeing to pay the bank $220 at the end of each month for 4 years. How much should the bank lend you if the agreed interest rate is 12% compounded monthly. Give your answer to the nearest dollar.
I went Total Money=220 {(1.12^48)-1} and then divided by 0.12 (Total of the terms of a GP).

(2) A person borrows $A dollar from a bank and agrees to pay the loan plus interest over a period of n years, the rate of interest being r% p.a. compouned annually. Prove that if (M subscript n) dollars is the annual repayment, then: M subscript n={A(R-1)R^n}/{R^n - 1} where R=1+ r/100.
I was unable to get the R^n on the numerator??