How do you solve 13-2n=19

After the seventh month of a 12-month loan: the numerator is: {(n + 11) + (n + 10) + (n + 9) + (n + 8) + (n + 7) + (n + 6) + (n + 5)} = , and the denominator is: {(n) + (n + 1) + + (n + 11)} = . therefore, the fraction is numerator/denominator (to the nearest tenth) = %

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

Which expression is not a polynomial?