\[\left( 43\frac{7^{\backslash 3}}{18} - 5\frac{2^{\backslash 6}}{9} \right) - 12\frac{8^{\backslash 2}}{27} =\]
\[= 38\frac{21 - 12}{54} - 12\frac{16}{54} =\]
\[= 38\frac{9}{54} - 12\frac{16}{54} =\]
\[= 37\frac{63}{54} - 12\frac{16}{54} = 25\frac{47}{54}\]