\[8\frac{3}{8} - \left( 5\frac{5}{6} + 1\frac{3}{4} \right) =\]
\[= 8\frac{3^{\backslash 3}}{8} - 5\frac{5^{\backslash 4}}{6} - 1\frac{3^{\backslash 6}}{4} =\]
\[= 8\frac{9}{24} - 5\frac{20}{24} - 1\frac{18}{24} =\]
\[= 8\frac{33}{24} - 5\frac{20}{24} - 1\frac{18}{24} =\]
\[= 3\frac{13}{24} - 1\frac{18}{24} = 2\frac{37}{24} - 1\frac{18}{24} = 1\frac{19}{24}.\]