\[\boxed{\mathbf{97}.}\]
\[1)\ \sqrt{3 - 2a}\]
\[3 - 2a \geq 0\]
\[- 2a \geq - 3\]
\[a \leq 1,5.\]
\[Ответ:при\ a \leq 1,5.\]
\[2)\ \sqrt{0,5a + 5}\]
\[0,5a + 5 \geq 0\]
\[0,5a \geq - 5\]
\[a \geq - 10.\]
\[Ответ:при\ a \geq - 10.\]
\[3)\ \sqrt{6 - \frac{2}{3}a}\]
\[6 - \frac{2}{3}a \geq 0\]
\[- \frac{2}{3}a \geq - 6\]
\[a \leq 6 \cdot \frac{3}{2}\]
\[a \leq 9.\]
\[Ответ:при\ a \leq 9.\]
\[4)\ \sqrt{- \frac{1}{2} - 3a}\]
\[- \frac{1}{2} - 3a \geq 0\]
\[- 3a \geq \frac{1}{2}\]
\[a \leq - \frac{1}{6}.\]
\[Ответ:при\ a \leq - \frac{1}{6}.\]