\(\left(2.x+\frac{1}{3}\right)^2=\frac{16}{25}\)
\(\Leftrightarrow2.x+\frac{1}{3}=\pm\sqrt{\frac{16}{25}}\)
\(\Leftrightarrow2.x+\frac{1}{3}=\pm\frac{4}{5}\)
\(\Leftrightarrow\orbr{\begin{cases}2.x+\frac{1}{3}=\frac{4}{5}\\2.x+\frac{1}{3}=-\frac{4}{5}\end{cases}}\Leftrightarrow\orbr{\begin{cases}2.x=\frac{7}{15}\\2.x=-\frac{17}{15}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{7}{30}\\x=-\frac{17}{30}\end{cases}}\)
\(\left(2.x+\frac{1}{3}\right)^2=\frac{16}{25}\)
\(\left(2.x+\frac{1}{3}\right)^2=\left(\frac{4}{5}\right)^2\)
\(\Rightarrow\orbr{\begin{cases}2.x+\frac{1}{3}=\frac{4}{5}\\2.x+\frac{1}{3}=\frac{-4}{5}\end{cases}\Rightarrow\orbr{\begin{cases}2.x=\frac{4}{5}-\frac{1}{3}\\2.x=\frac{-4}{5}-\frac{1}{3}\end{cases}\Rightarrow}\orbr{\begin{cases}2.x=\frac{12}{15}-\frac{5}{15}\\2.x=\frac{-12}{15}-\frac{5}{15}\end{cases}\Rightarrow}\orbr{\begin{cases}2.x=\frac{7}{15}\\2.x=\frac{-17}{15}\end{cases}}}\)\(\Rightarrow\orbr{\begin{cases}x=\frac{7}{15}:2\\x=\frac{-17}{15}:2\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{7}{15}.\frac{1}{2}\\x=\frac{-17}{15}.\frac{1}{2}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{7}{30}\\x=\frac{-17}{30}\end{cases}}}\)
Vậy \(x=\frac{7}{30}\)hoặc \(x=\frac{-17}{30}\)
