выполните сложение - 2 1/6 + 3 1/15; 2) -4 7/9 + 5/6; 3) 5 2/7+(-3 7/8).

\displaystyle 1)..-2 \frac{1}{6}+3 \frac{1}{15}= \frac{92}{30}- \frac{65}{30}= \frac{27}{30}=0,9 \\ \\ 2)..-4 \frac{7}{9}+ \frac{5}{6}=-4 \frac{14}{18}+ \frac{15}{18}=-3 \frac{32}{18}+ \frac{15}{18}=-3 \frac{17}{18} \\ \\3)..5 \frac{2}{7}+(-3 \frac{7}{8})= \frac{37}{7}- \frac{31}{8}= \frac{296-217}{56}= \frac{79}{56}=1 \frac{23}{56}