\(\rightarrow3\left(9x^2-1\right)=0\\ \rightarrow9x^2-1=0\\ \rightarrow9x^2=1\\ \rightarrow3x=1hoặc3x=-1\\ TH1:3x=1\\ \rightarrow x=\dfrac{1}{3}\\ TH2:3x=-1\\ \rightarrow x=-\dfrac{1}{3}\)
\(27x^2-3=0\)
\(\Leftrightarrow27x^2=3\)
\(\Leftrightarrow x^2=\dfrac{1}{9}\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=-\dfrac{1}{3}\end{matrix}\right.\)