\[a^{2}x^{2} + ax - 2 = 0;\ \ \ \ \ x = \frac{1}{3}\]
\[a^{2} \cdot \left( \frac{1}{3} \right)^{2} + a \cdot \frac{1}{3} - 2 = 0\]
\[\frac{1}{9}a² + \frac{1}{3}a - 2 = 0\ \ \ \ \ \ \ \ \ \ | \cdot 9\]
\[a^{2} + 3a - 18 = 0\]
\[D = 3^{2} - 4 \cdot 1 \cdot ( - 18) =\]
\[= 9 + 72 = 81\]
\[a_{1} = \frac{- 3 + \sqrt{81}}{2 \cdot 1} = \frac{- 3 + 9}{2} =\]
\[= \frac{6}{2} = 3;\]
\[a_{2} = \frac{- 3 - \sqrt{81}}{2 \cdot 1} = \frac{- 3 - 9}{2} =\]
\[= \frac{- 12}{2} = - 6\]
\[Ответ:при\ a = 3;\ a = - 6.\]