[tex]16x^2-16x+4=9 \\
(4x)^2-2 \cdot 2 \cdot 4x + 2^2=9 \\
(4x-2)^2=9 \\
\sqrt{(4x-2)^2}=\sqrt{9} \\
|4x-2|=3 \\
4x-2=3 \ \lor \ 4x-2=-3 \\
4x=5 \ \lor \ 4x=-1 \\
x=\frac{5}{4} \ \lor \ x=-\frac{1}{4} \\
\boxed{x \in \{ -\frac{1}{4}, \frac{5}{4} \} }[/tex]