URGENT please help! I have a few hours to finish this assignment or I will fail :(

1foot = 12 inches; 1 yard = 3 feet

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

How do you use the elimination method for this question? explain, because i really want to understand!