\[\frac{x^{2}}{(2x - 1)^{2}} - \frac{4x}{2x - 1} + 3 = 0\]
\[Пусть\ \ t = \frac{x}{2x - 1};\ \ x \neq \frac{1}{2}:\ \]
\[t² - 4t + 3 = 0\]
\[t_{1} + t_{2} = 4;\ \ t_{1} \cdot t_{2} = 3\]
\[t_{1} = 3,\ \ t_{2} = 1.\]