1: \(\left(-\dfrac{2}{3}+\dfrac{10}{7}\right):\dfrac{4}{5}+\left(-\dfrac{1}{3}+\dfrac{4}{7}\right):\dfrac{4}{5}\)
\(=\left(-\dfrac{2}{3}+\dfrac{10}{7}+\dfrac{-1}{3}+\dfrac{4}{7}\right):\dfrac{4}{5}\)
\(=\left(\dfrac{14}{7}-\dfrac{3}{3}\right)\cdot\dfrac{5}{4}=\left(2-1\right)\cdot\dfrac{5}{4}=\dfrac{5}{4}\)
2: \(\left(-\dfrac{3}{4}+\dfrac{2}{3}\right):\dfrac{5}{11}+\left(-\dfrac{1}{4}+\dfrac{1}{3}\right):\dfrac{5}{11}\)
\(=\left(-\dfrac{3}{4}+\dfrac{2}{3}+\dfrac{-1}{4}+\dfrac{1}{3}\right):\dfrac{5}{11}\)
\(=\left(-\dfrac{4}{4}+\dfrac{3}{3}\right):\dfrac{5}{11}=\left(-1+1\right)\cdot\dfrac{11}{5}\)
=0
3: \(\left(-\dfrac{1}{5}+\dfrac{3}{7}\right):\dfrac{2}{11}+\left(-\dfrac{4}{5}+\dfrac{4}{7}\right):\dfrac{2}{11}\)
\(=\left(-\dfrac{1}{5}+\dfrac{3}{7}+\dfrac{-4}{5}+\dfrac{4}{7}\right):\dfrac{2}{11}\)
\(=\left(-\dfrac{5}{5}+\dfrac{7}{7}\right)\cdot\dfrac{11}{2}=0\)
4: \(\left(-\dfrac{3}{7}+\dfrac{1}{12}\right):\dfrac{-5}{6}-\left(-\dfrac{10}{7}+\dfrac{13}{12}\right):\dfrac{-5}{6}\)
\(=\left(-\dfrac{3}{7}+\dfrac{1}{12}-\dfrac{-10}{7}-\dfrac{13}{12}\right):\dfrac{-5}{6}\)
\(=\left(-\dfrac{3}{7}+\dfrac{10}{7}+\dfrac{1}{12}-\dfrac{13}{12}\right):\dfrac{-5}{6}\)
\(=\left(\dfrac{7}{7}-\dfrac{13}{12}\right)\cdot\dfrac{6}{-5}=0\)
\(1,\left(\dfrac{-2}{3}+\dfrac{10}{7}\right):\dfrac{4}{5}+\left(\dfrac{-1}{3}+\dfrac{4}{7}\right):\dfrac{4}{5}\)
\(=\left(\dfrac{-14}{21}+\dfrac{30}{21}\right).\dfrac{5}{4}+\left(\dfrac{-7}{21}+\dfrac{12}{21}\right).\dfrac{5}{4}\)
\(=\dfrac{16}{21}.\dfrac{5}{4}+\dfrac{5}{21}.\dfrac{5}{4}\)
\(=\dfrac{5}{4}.\left(\dfrac{16}{21}+\dfrac{5}{21}\right)\)
\(=\dfrac{5}{4}.1\)
\(=\dfrac{5}{4}\)
\(2,\left(\dfrac{-3}{4}+\dfrac{2}{3}\right):\dfrac{5}{11}+\left(\dfrac{-1}{4}+\dfrac{1}{3}\right):\dfrac{5}{11}\)
\(=\left(\dfrac{-9}{12}+\dfrac{8}{12}\right).\dfrac{11}{5}+\left(\dfrac{-3}{12}+\dfrac{4}{12}\right).\dfrac{11}{5}\)
\(=\dfrac{-1}{12}.\dfrac{11}{5}+\dfrac{1}{12}.\dfrac{11}{5}\)
\(=\dfrac{11}{5}.\left(\dfrac{-1}{12}+\dfrac{1}{12}\right)\)
\(=\dfrac{11}{15}.0\)
\(=0\)
\(3,\left(\dfrac{-1}{5}+\dfrac{3}{7}\right):\dfrac{2}{11}+\left(-\dfrac{4}{5}+\dfrac{4}{7}\right):\dfrac{2}{11}\)
\(=\left(\dfrac{-7}{35}+\dfrac{15}{35}\right).\dfrac{11}{2}+\left(\dfrac{-28}{35}+\dfrac{20}{35}\right).\dfrac{11}{2}\)
\(=\dfrac{8}{35}.\dfrac{11}{2}+\dfrac{-8}{35}.\dfrac{11}{2}\)
\(=\dfrac{11}{2}.\left(\dfrac{8}{35}+\dfrac{-8}{35}\right)\)
\(=\dfrac{11}{2}.0\)
\(=0\)
\(4,\left(\dfrac{-3}{7}+\dfrac{1}{12}\right):\dfrac{-5}{6}-\left(\dfrac{-10}{7}+\dfrac{13}{12}\right):\dfrac{-5}{6}\)
\(=\left(\dfrac{-36}{84}+\dfrac{7}{84}\right).\dfrac{-6}{5}-\left(\dfrac{-120}{84}+\dfrac{91}{84}\right).\dfrac{-6}{5}\)
\(=\dfrac{-29}{84}.\dfrac{-6}{5}-\dfrac{-29}{84}.\dfrac{-6}{5}\)
\(=\dfrac{-6}{5}.\left(\dfrac{-29}{84}-\dfrac{-29}{84}\right)\)
\(=\dfrac{-6}{5}.0\)
\(=0\)
