\(a,\dfrac{29}{19}+\dfrac{-7}{15}+\dfrac{-8}{15}-\dfrac{10}{19}=\left(\dfrac{29}{19}-\dfrac{10}{19}\right)+\left(\dfrac{-7}{15}+\dfrac{-8}{15}\right)=\dfrac{19}{19}+\dfrac{-15}{15}=1+\left(-1\right)=0\\ b,\dfrac{-7}{9}.\dfrac{6}{13}+\dfrac{-7}{9}.\dfrac{7}{13}+\dfrac{7}{9}=\dfrac{-7}{9}\left(\dfrac{6}{13}+\dfrac{7}{13}\right)+\dfrac{7}{9}=\dfrac{-7}{9}.\dfrac{13}{13}+\dfrac{7}{9}=\dfrac{-7}{9}.1+\dfrac{7}{9}=\dfrac{-7}{9}+\dfrac{7}{9}=0\)
\(c,\dfrac{-3}{7}+\dfrac{15}{26}-\left(\dfrac{2}{13}-\dfrac{3}{7}\right)=\dfrac{-3}{7}+\dfrac{15}{26}-\dfrac{4}{26}+\dfrac{3}{7}=\left(\dfrac{-3}{7}+\dfrac{3}{7}\right)+\left(\dfrac{15}{26}-\dfrac{4}{26}\right)=\dfrac{0}{7}+\dfrac{11}{26}=0+\dfrac{11}{26}=\dfrac{11}{26}\\ d,2.\dfrac{3}{7}+\left(\dfrac{2}{9}-1\dfrac{3}{7}\right)-\dfrac{5}{3}:\dfrac{1}{9}=\dfrac{6}{7}+\dfrac{2}{9}-\dfrac{10}{7}-15=-\dfrac{967}{63}\)
