\(\boxed{\mathbf{2.}\mathbf{339}\mathbf{.\ ОК\ ГДЗ - домашка\ на\ }5}\)
\[\textbf{а)}\ \left( 1\frac{1}{5} \right)^{2} = \left( \frac{6}{5} \right)^{2} = \frac{36}{25} = 1\frac{9}{25}\]
\[\textbf{б)}\ \left( \frac{3}{4} - \frac{2}{3} \right)^{2} = \left( \frac{9}{12} - \frac{8}{12} \right)^{2} =\]
\[= \left( \frac{1}{12} \right)^{2} = \frac{1}{144}.\]
\[\textbf{в)}\ \left( \frac{1}{3} \right)^{2} - \left( \frac{1}{9} \right)^{2} = \frac{1^{\backslash 9}}{9} - \frac{1}{81} =\]
\[= \frac{9}{81} - \frac{1}{81} = \frac{8}{81}\]