A possible value of ' $x$ ', for which the ninth term in the expansion of $\left\{3^{\log _3 \sqrt{25^{x-1}+7}}+3^{\left(-\frac{1}{8}\right) \log _3\left(5^{x-1}+1\right)}\right\}^{10}$ in the increasing powers of $3^{\left(-\frac{1}{8}\right) \log _3\left(5^{x-1}+1\right)}$ is equal to 180 , is:
