Question

tìm x biết

2-25x²=0

Answer 1

\(2-25x^2=0\\ \Leftrightarrow-25x^2=-2\\ \Leftrightarrow x^2=\dfrac{2}{25}\\ \Leftrightarrow x=\sqrt{\dfrac{2}{25}}\)

Answer 2

\(\Leftrightarrow\left(\sqrt{2}\right)^2-\left(5x\right)^2=0\)

\(\Leftrightarrow\left(\sqrt{2}-5x\right)\left(\sqrt{2}+5x\right)=0\)

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

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