Ta có: M=\(\frac{155-\frac{10}{7}-\frac{5}{11}+\frac{5}{23}}{403-\frac{26}{7}-\frac{13}{11}+\frac{13}{23}}\)+\(\frac{\frac{3}{5}+\frac{3}{13}-0,9}{\frac{7}{91}+0,2-\frac{3}{10}}\)
=\(\frac{5.\left(31-\frac{2}{7}-\frac{1}{11}+\frac{1}{23}\right)}{13.\left(31-\frac{2}{7}-\frac{1}{11}+\frac{1}{23}\right)}\)+\(\frac{\frac{9}{15}+\frac{9}{39}-\frac{9}{10}}{\frac{1}{13}+\frac{1}{5}+\frac{3}{10}}\)
=\(\frac{5}{13}\)+\(\frac{9.\left(\frac{1}{15}+\frac{1}{39}-\frac{1}{10}\right)}{3.\left(\frac{1}{39}+\frac{1}{15}-\frac{1}{10}\right)}\)
=\(\frac{5}{13}\)+\(\frac{9}{3}\)
=\(\frac{5}{13}\)+3
=\(\frac{44}{13}\)
