\(\left(5-7x\right)\left(\dfrac{3}{7}-3x\right)=0\)
\(=>\left\{{}\begin{matrix}5-7x=0\\\dfrac{3}{7}-3x=0\end{matrix}\right.=>\left\{{}\begin{matrix}x=\dfrac{5}{7}\\x=\dfrac{1}{7}\end{matrix}\right.\)
\(\left(5-7x\right)\left(\dfrac{3}{7}-3x\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}5-7x=0\\\dfrac{3}{7}-3x=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}7x=5\\3x=\dfrac{3}{7}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{7}\\x=\dfrac{1}{7}\end{matrix}\right.\)
Vậy x = \(\dfrac{5}{7}\) hoặc x=\(\dfrac{1}{7}\)