|\(\dfrac{3}{4}-\left|x-\dfrac{1}{4}\right|\)|\(-\dfrac{1}{2}=\dfrac{3}{4}\)
\(\Leftrightarrow\)|\(\dfrac{3}{4}-\left|x-\dfrac{1}{4}\right|\)|=\(\dfrac{5}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{3}{4}-\left|x-\dfrac{1}{4}\right|=\dfrac{5}{4}\\\dfrac{3}{4}-\left|x-\dfrac{1}{4}\right|=-\dfrac{5}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left|x-\dfrac{1}{4}\right|=-\dfrac{1}{2}\left(loại\right)\\\left|x-\dfrac{1}{4}\right|=2\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{1}{4}=2\\x-\dfrac{1}{4}=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{9}{4}\\x=-\dfrac{7}{4}\end{matrix}\right.\)
