\[\sqrt{- 0,53 \cdot (6,2a - 24,8)}\]
\[- 0,53 \cdot (6,2a - 24,8) \geq 0\]
\[6,2a - 24,8 \leq 0\]
\[6,2a \leq 24,8\]
\[a \leq 4.\]
\[Ответ:4)\ ( - \infty;4\rbrack.\]