Ответ:

\(\frac{3}{5}-\frac{11}{20}=\frac{12}{20}-\frac{11}{20}=\frac{1}{20}\).

\(\frac{10}{70}-\frac{4}{210}=\frac{30}{210}-\frac{4}{210}=\frac{26}{210}=\frac{13}{105}\).

Ответ: \(\frac{1}{20};\ \frac{13}{105}\).