$$( \frac { 7 } { 9 } ) ^ { - 4 } \times ( \frac { 7 } { 9 } ) ^ { 3 x } = ( \frac { 9 } { 7 } ) ^ { - 5 }$$
$x=3$
$x=\frac{2\pi n_{1}i}{3\ln(\frac{7}{9})}+\frac{\log_{\frac{7}{9}}\left(\frac{40353607}{387420489}\right)}{3}$
$n_{1}\in \mathrm{Z}$
