Ответ:
\(\frac{7}{21}\cdot\frac{8}{65}-\frac{5}{42}=\frac{8}{195}-\frac{5}{42}=\frac{112-325}{2730}=-\frac{213}{2730}=-\frac{71}{910}\).
Ответ: −71
\(\frac{7}{21}\cdot\frac{8}{65}-\frac{5}{42}=\frac{8}{195}-\frac{5}{42}=\frac{112-325}{2730}=-\frac{213}{2730}=-\frac{71}{910}\).
Ответ: −71