\[\boxed{\mathbf{2.430}}\]
\[\textbf{а)}\ \left( \frac{4}{7} + \frac{3}{7} \right)\ :100 = 1\ :100 =\]
\[= 0,01\]
\[\textbf{б)}\ \left( \frac{3^{\backslash 6}}{5} + \frac{5^{\backslash 5}}{6} \right) \cdot \frac{30}{43} =\]
\[= \left( \frac{18}{30} + \frac{25}{30} \right) \cdot \frac{30}{43} = \frac{43}{30} \cdot \frac{30}{43} = 1\]
\[\textbf{в)}\ \left( 1\frac{2}{3} - \frac{2}{3} \right)\ :\frac{2}{9} = 1\ :\frac{2}{9} = \frac{9}{2} =\]
\[= 4\frac{1}{2}\]
\[\textbf{г)}\ \left( \frac{8}{21} - \frac{2^{\backslash 3}}{7} \right) \cdot 10\frac{1}{2} =\]
\[= \left( \frac{8}{21} - \frac{6}{21} \right) \cdot \frac{21}{2} = \frac{2}{21} \cdot \frac{21}{2} = 1\]