Đáp án:
\(\begin{array}{l}
2)x = 2\\
3)\left[ \begin{array}{l}
x = - 3\\
x = 12
\end{array} \right.
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
2)DK:x \ge 2\\
\sqrt {\left( {x - 2} \right)\left( {x + 2} \right)} - 2\sqrt {x - 2} = 0\\
\to \sqrt {x - 2} \left( {\sqrt {x + 2} - 2} \right) = 0\\
\to \left[ \begin{array}{l}
x - 2 = 0\\
\sqrt {x + 2} = 2
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 2\\
x + 2 = 4
\end{array} \right.\\
\to x = 2\\
3)DK:\left[ \begin{array}{l}
x \ge 3\\
x = - 3
\end{array} \right.\\
\sqrt {\left( {x - 3} \right)\left( {x + 3} \right)} - 3\sqrt {x + 3} = 0\\
\to \sqrt {x + 3} \left( {\sqrt {x - 3} - 3} \right) = 0\\
\to \left[ \begin{array}{l}
x + 3 = 0\\
\sqrt {x - 3} = 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = - 3\\
x - 3 = 9
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = - 3\\
x = 12
\end{array} \right.
\end{array}\)
( câu 1 bạn chụp thiếu đề nhé )
