Giải thích các bước giải:
a) $\frac{-3}{7}$ + $\frac{17}{26}$ - $\frac{2}{13}$ + $\frac{3}{7}$
= ($\frac{-3}{7}$ + $\frac{3}{7}$) - $\frac{2}{13}$ + $\frac{17}{26}$
= 0 + $\frac{2}{13}$ + $\frac{17}{26}$
= $\frac{2}{13}$ + $\frac{17}{26}$
= $\frac{4}{26}$ + $\frac{17}{26}$
= $\frac{21}{26}$
b) 1$\frac{3}{15}$ - ($\frac{11}{20}$ + 25%)
= $\frac{18}{15}$ - ($\frac{11}{20}$ + $\frac{1}{4}$)
= $\frac{6}{5}$ - ($\frac{11}{20}$ + $\frac{5}{20}$)
= $\frac{6}{5}$ - $\frac{4}{5}$
= $\frac{6}{5}$ + $\frac{-4}{5}$
= $\frac{2}{5}$
c) $\frac{-3}{7}$ . $\frac{5}{11}$ + $\frac{6}{11}$ . $\frac{-3}{7}$ + 5$\frac{3}{7}$
= $\frac{-3}{7}$ . ($\frac{5}{11}$ + $\frac{6}{11}$) + $\frac{38}{7}$
= $\frac{-3}{7}$ . 1 + $\frac{38}{7}$
= $\frac{-3}{7}$ + $\frac{38}{7}$
= $\frac{35}{7}$
= 5
