\[1)\arccos(x - 3) = \frac{3\pi}{4}\]
\[x - 3 = - \frac{\sqrt{2}}{2}\]
\[x = 3 - \frac{\sqrt{2}}{2}\]
\[Ответ:\ \ 3 - \frac{\sqrt{2}}{2}.\]
\[2)\arcsin\left( \frac{x + 2}{3} \right) = - \frac{\pi}{6}\]
\[\frac{x + 2}{3} = - \frac{1}{2}\]
\[2x + 4 = - 3\]
\[2x = - 7\]
\[x = - 3,5\]
\[Ответ:\ - 3,5.\]