69. suppose that you currently have one credit card with a balance of $10,000 at an annual rate of 24.00% interest. you have stopped adding any additional charges to this card and are determined to pay off the balance. you have worked out the formula bbn = b0r n − r(1 + r+r2 ++ r n−1), where b0 is the initial balance, bn is the balance after you have maden payments, r= 1 + i, wherei is the monthly interest rate, and r is the amount you are planning to pay each month.
a. what is the monthly interest rate i ? what is the growth rate, r ?