Ответ:

  1. \(\left(\frac{1}{12}-\frac{17}{15}\right)\cdot\frac{10}{3}=\left(\frac{5}{60}-\frac{68}{60}\right)\cdot\frac{10}{3}= -\frac{21}{20}\cdot\frac{10}{3}=-\frac{7}{2}\).

  2. \(\left(\frac{7}{15}+\frac{19}{30}\right)\cdot\frac{9}{11}=\left(\frac{14}{30}+\frac{19}{30}\right)\cdot\frac{9}{11}=\frac{11}{10}\cdot\frac{9}{11}=\frac{9}{10}\).

  3. \(\left(\frac{3}{25}-\frac{2}{35}\right)\cdot14=\left(\frac{21}{175}-\frac{10}{175}\right)\cdot14=\frac{11}{175}\cdot14=\frac{22}{25}\).

  4. \(\left(\frac{1}{30}+\frac{7}{10}\right)\cdot(-6)=\left(\frac{1}{30}+\frac{21}{30}\right)\cdot(-6)=\frac{11}{15}\cdot(-6)=-\frac{22}{5}\).

Ответ: 1) −7/2; 2) 9/10; 3) 22/25; 4) −22/5.