\[\left( 3,5\ :\frac{5}{7} - 3,5 \cdot \frac{5}{7} \right)\ :0,3 =\]
\[= \left( \frac{35 \cdot 7}{10 \cdot 8} - \frac{35 \cdot 5}{10 \cdot 7} \right):\frac{3}{10} =\]
\[= \left( \frac{49^{\backslash 7}}{10} - \frac{35^{\backslash 5}}{14} \right) \cdot \frac{10}{3} =\]
\[= \frac{343 - 175\ }{70} \cdot \frac{10}{3} = \frac{168 \cdot 10}{70 \cdot 3} =\]
\[= 8 - число.\]