Вопрос:

Ответ:

\[\sqrt{a(x - 3)} = 0\ \ \]

\[x - 3 = 0\ \ \]

\[x = 3.\]

\[a = 0 \Longrightarrow x - любое.\]

\[a \neq 0 \Longrightarrow x = 3.\]