You have a credit card that has a balance of $$6840$ at an APR of $9\mathrm{.}99\%.$ You plan to pay $$400$ each month in an effort to clear the debt quickly. How many months will it take you to pay off the balance?the last year the value of my car depreciated by $30\%.$ If the value of my car is $$19,000$ today, then what was the value of my car one year ago? Round your answer to the nearest cent, if necessary $.$