\(\dfrac{4}{9}-25x^2=0\)
\(\left(\dfrac{2}{3}\right)^2-\left(5x\right)^2=0\)
\(\left(\dfrac{2}{3}+5x\right)\left(\dfrac{2}{3}-5x\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}\dfrac{2}{3}+5x=0\\\dfrac{2}{3}-5x=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}5x=-\dfrac{2}{3}\\-5x=-\dfrac{2}{3}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{2}{15}\\x=\dfrac{2}{15}\end{matrix}\right.\)
