\[\boxed{\mathbf{2.}\mathbf{355}}\]
\[\textbf{а)}\ 1 - \frac{1}{4} = \frac{4}{4} - \frac{1}{4} = \frac{3}{4}.\]
\[\textbf{б)}\ \frac{3}{4} - \frac{1}{4} = \frac{2}{4} = \frac{1}{2}.\]
\[\textbf{в)}\ \frac{1^{\backslash 2}}{2} - \frac{1}{4} = \frac{2}{4} - \frac{1}{4} = \frac{1}{4}.\]
\[\textbf{г)}\ 1\frac{1}{8} - \frac{1^{\backslash 2}}{4} = \frac{9}{8} - \frac{2}{8} = \frac{7}{8}.\]
\[\textbf{д)}\ 1\frac{1}{12} - \frac{1^{\backslash 3}}{4} = \frac{13}{12} - \frac{3}{12} = \frac{10}{12} =\]
\[= \frac{5}{6}.\]