Toán Lớp 9: √9???? − 6√???? + 1 − 2√???? = 1
CĂN TẤT CẢ 9???? − 6√???? + 1 – 2√???? = 1
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Toán Lớp 9: √9???? − 6√???? + 1 − 2√???? = 1
CĂN TẤT CẢ 9???? − 6√???? + 1 – 2√???? = 1
giúp mình vói
Comments ( 1 )
Dkxd:x \ge 0\\
\sqrt {9x – 6\sqrt x + 1} – 2\sqrt x = 1\\
\Leftrightarrow \sqrt {{{\left( {3\sqrt x } \right)}^2} – 2.3\sqrt x + 1} = 2\sqrt x + 1\\
\Leftrightarrow \sqrt {{{\left( {3\sqrt x – 1} \right)}^2}} = 2\sqrt x + 1\\
\Leftrightarrow \left| {3\sqrt x – 1} \right| = 2\sqrt x + 1\\
\Leftrightarrow \left[ \begin{array}{l}
3\sqrt x – 1 = 2\sqrt x + 1\\
3\sqrt x – 1 = – 2\sqrt x – 1
\end{array} \right.\\
\Leftrightarrow \left[ \begin{array}{l}
\sqrt x = 2\\
\sqrt x = 0
\end{array} \right.\\
\Leftrightarrow \left[ \begin{array}{l}
x = 4\left( {tm} \right)\\
x = 0\left( {tm} \right)
\end{array} \right.\\
Vậy\,x = 0;x = 4
\end{array}$