Ta có:
\(\sqrt{4x^2-4x+1}\)=\(\sqrt{\left(2x-1\right)^2}\)=\(\left|2x-1\right|\)=2015 \(\Rightarrow\) \(\left[{}\begin{matrix}2x-1=2015\\2x-1=-2015\end{matrix}\right.\)\(\Leftrightarrow\)\(\left[{}\begin{matrix}2x=2016\\2x=-2014\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1008\\x=-1007\end{matrix}\right.\)
Vậy S=\(\left\{-1007;1008\right\}\)