\[x^{2}\]
\[x = 7:\]
\[x^{2} = 7^{2} = 49.\]
\[x = - 11:\]
\[x^{2} = ( - 11)^{2} = 11^{2} = 121.\]
\[x = 0,8:\]
\[x^{2} = (0,8)^{2} = 0,64.\]
\[x = - \frac{4}{5}:\]
\[x^{2} = \left( - \frac{4}{5} \right)^{2} = \left( \frac{4}{5} \right)^{2} = \left( \frac{8}{10} \right)^{2} =\]
\[= (0,8)^{2} = 0,64.\]
\[x = 1\frac{1}{3} = \frac{4}{3}:\]
\[x^{2} = \left( \frac{4}{3} \right)^{2} = \frac{4^{2}}{3^{2}} = \frac{16}{9} = 1\frac{7}{9}\text{.\ }\]