\[9x^{2} - 6x + 1 = 0\ \ \ \ \ \ \]
\[D = 36 - 36 = 0\]
\[(3x - 1)^{2} = 0\]
\[3x = 1\]
\[x = \frac{1}{3}.\]
\[Ответ:x = \frac{1}{3}.\]