13. \(\left(\dfrac{3}{25}-\dfrac{2}{35}\right)\cdot14\)

Общий знаменатель дробей — 175: \(\dfrac{3}{25}=\dfrac{21}{175}\), \(\dfrac{2}{35}=\dfrac{10}{175}\).

\(\dfrac{21}{175}-\dfrac{10}{175}=\dfrac{11}{175}\).

\(\dfrac{11}{175}\cdot14=\dfrac{154}{175}=\dfrac{22}{25}\).

Ответ: \(\dfrac{22}{25}\).