Решите неравенство: x-5*корень из x+6<=0.

\[x - 5\sqrt{x} + 6 \leq 0;\ \ \ t = \sqrt{x}\]

\[t^{2} - 5t + 6 \leq 0\]

\[(t - 3)(t - 2) \leq 0\]

\[2 \leq t \leq 3 \Longrightarrow 2 \leq \sqrt{x} \leq 3 \Longrightarrow\]

\[\Longrightarrow 4 \leq x \leq 9\ \]

\[Ответ:\lbrack 4;9\rbrack.\]