Вопрос:

Ответ:

\[\sqrt{2x + 1} = \sqrt{2 \cdot 5 - 1}\]

\[\sqrt{2x + 1} = \sqrt{9}\]

\[2x + 1 = 9\]

\[2x = 9 - 1\]

\[2x = 8\]

\[x = 4.\]

\[Ответ:x = 4.\ \]