[tex]\it 0,(3)x^2=\dfrac{27}{256} \Leftrightarrow \dfrac{3}{9}x^2=\dfrac{27}{256} \Leftrightarrow \dfrac{x^2}{3} =\dfrac{27}{256} \Leftrightarrow x^2 = \dfrac{81}{256} \Leftrightarrow \\ \\ \\ \Leftrightarrow x^2=\dfrac{9^2}{16^2} \Leftrightarrow \sqrt{x^2} =\sqrt{\dfrac{9^2}{16^2}} \Leftrightarrow |x| =\dfrac{9}{16} \Leftrightarrow x = \pm\dfrac{9}{16}[/tex]