[tex]\displaystyle
\Big[ \sqrt{6561} \times\frac{-3,4(1)}{-27,9}-\Big(\frac{4}{3}\Big)^{-2}\times0,(4)\Big] \times \Big(\frac{6}{\sqrt{7}}\Big)^2\times\frac{1}{10}=\\\\
=\Big[81\times\frac{3,4(1)}{27,9}-\frac{9}{16}\times\frac{4}{9}\Big]\times\frac{36}{7} \times\frac{1}{10}=\\\\
=\Big[81\times\frac{\frac{341-34}{90}}{\frac{279}{10}}-\frac{1}{4}\Big]\times\frac{18}{35}=\\\\
=\Big[ 81 \times \frac{307}{90} \times \frac{10}{279}-\frac{1}{4}\Big]\times\frac{18}{35}= [/tex]
[tex]\displaystyle
=\Big[ \frac{81 \times307\times 10}{90 \times 279}-\frac{1}{4}\Big]\times\frac{18}{35}= \\\\
=\Big[ \frac{307}{ 31}-\frac{1}{4}\Big]\times\frac{18}{35}= \\ \\
=\Big[ \frac{307\times 4 - 1\times 31}{31\times 4}\Big]\times\frac{18}{35}= \\ \\
=\frac{1228 - 31}{31\times 124} \times\frac{18}{35}= \\ \\
=\frac{1197}{ 124} \times\frac{18}{35}= \frac{171}{ 62} \times\frac{9}{5}= \boxed{\frac{1539}{310} }[/tex]
