\[9x^{2} - 16 = 0\]
\[9x^{2} = 16\]
\[x^{2} = \frac{16}{9}\]
\[x = \pm \frac{4}{3}\]
\[x = \pm 1\frac{1}{3}.\]
\[Ответ:x = \pm 1\frac{1}{3}.\]