\[4\frac{9}{10} - \left( 1\frac{5^{\backslash 2}}{12} + 1\frac{11}{24} \right) =\]
\[= 4\frac{9}{10} - \left( 1\frac{10}{24} + 1\frac{11}{24} \right) =\]
\[= 4\frac{9}{10} - 2\frac{21}{24} = 4\frac{9^{\backslash 4}}{10} - 2\frac{7^{\backslash 5}}{8} =\]
\[= 4\frac{36}{40} - 2\frac{35}{40} = 2\frac{1}{40}.\]