• # question_answer 10) Which of the following sum is in the simplest form? A)  $\frac{4}{9}+\frac{-5}{9}$                       B)  $\frac{-2}{5}+\frac{13}{20}$       C)         $\frac{-5}{12}+\frac{11}{-12}$    D)         $\frac{-7}{8}+\frac{1}{12}+\frac{2}{3}$

(a) $\frac{4}{9}+\frac{-5}{9}=\frac{4-5}{9}=\frac{-1}{9}$ (b) $\frac{-2}{5}+\frac{13}{20}=\frac{-8+13}{20}=\frac{5}{20}$ (c) $\frac{-5}{12}+\frac{11}{-12}=\frac{-5}{12}-\frac{11}{12}=\frac{-5-11}{12}=\frac{-16}{12}$ (d) $\frac{-7}{8}+\frac{1}{12}+\frac{2}{3}=\frac{-21+2+16}{24}=\frac{-3}{24}$ $\therefore$ Option (a) is in simplest form,