Question

\(\sqrt{4x^2}=6\)

\(\sqrt{9x^2=}\left|-12\right|\)

\(x^2-5=0\)

\(\sqrt{16}=8\)

Answer 1

√16=8??????????? ai c/m giùm

Answer 2

\(\sqrt{16}=8\) Rì lý :))

Answer 3

\(\sqrt{4x^2}=6\\ \Leftrightarrow\left|2x\right|=6\\ \Leftrightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)

\(\sqrt{9x^2}=\left|-12\right|\\ \Leftrightarrow\left|3x\right|=12\\ \Leftrightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

\(x^2-5=0\\ \Leftrightarrow\left(x-\sqrt{5}\right)\left(x+\sqrt{5}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-\sqrt{5}=0\\x+\sqrt{5}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\sqrt{5}\\x=-\sqrt{5}\end{matrix}\right.\)