\[ \sqrt{25(x - 1)} - \frac{15}{2} \sqrt{\frac{x - 1}{9}} = 6 + \sqrt{x + 1}. \]

----- Nội dung ảnh -----
\[
\sqrt{25(x - 1)} - \frac{15}{2} \sqrt{\frac{x - 1}{9}} = 6 + \sqrt{x + 1}.
\]