Question

Tìm nghiệm của phương trình \(\sqrt{x^2-4}-3\sqrt{x-2}=0\)

Answer 1

\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+2=9\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=7\end{matrix}\right.\)

Answer 2

\(ĐK:x\ge2\\ PT\Leftrightarrow\sqrt{x-2}\left(\sqrt{x+2}-3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}\sqrt{x-2}=0\\\sqrt{x+2}=3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+2=9\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\left(tm\right)\\x=7\left(tm\right)\end{matrix}\right.\)

Answer 3

ĐK:x≥2PT⇔√x−2(√x+2−3)=0⇔[√x−2=0√x+2=3⇔[x−2=0x+2=9⇔[x=2(tm)x=7(tm)