\(2-25x^2=0\Rightarrow\left(\sqrt{2}\right)^2-\left(5x\right)^2=0\)
\(\Rightarrow\left(\sqrt{2}-5x\right)\left(\sqrt{2}+5x\right)=0\)
Hoặc \(\sqrt{2}-5x=0\Rightarrow5x=\sqrt{2}\Rightarrow x=\frac{\sqrt{2}}{5}\)
Hoặc \(\sqrt{2}+5x=0\Rightarrow5x=-\sqrt{2}\Rightarrow x=-5\)
\(2-25x^2=0\)
\(\Rightarrow25x^2=2-0=2\)
\(x^2=\frac{2}{25}\)
\(x=\frac{1}{5}.\sqrt{2}\)
\(2-25x^2=0\)
\(=>25x^2=2-0=2\)
\(=>x^2=\frac{2}{25}\)
\(=>x=\frac{1}{5}.\sqrt{2}\)
Tự tính nha
\(2-25x^2=0\)
\(\Leftrightarrow\left(\sqrt{2}\right)^2-\left(5x\right)^2=0\)
\(\Leftrightarrow\left(\sqrt{2}+5x\right)\left(\sqrt{2x}-5\right)=0\)
\(\Leftrightarrow\sqrt{2}+5x=0\)Hoặc \(\sqrt{2}-5x=0\)
\(\Leftrightarrow5x=-\sqrt{2}\) hoặc \(5x=\sqrt{2}\)
\(\Leftrightarrow x=\frac{-\sqrt{2}}{5}\) hoặc \(x=\frac{\sqrt{2}}{5}\)
\(S=\left\{\frac{-\sqrt{2}}{5};\frac{\sqrt{2}}{5}\right\}\)
