\[3x^{2} - 7x + 3 = 0\]
\[\left\{ \begin{matrix} x_{1} + x_{2} = \frac{7}{3} \\ x_{1} \cdot x_{2} = 1\ \ \\ \end{matrix} \right.\ \]
\[1)\ 3x_{1} + 3x_{2} = 3 \cdot \left( x_{1} + x_{2} \right) =\]
\[= 3 \cdot \frac{7}{3} = 7\]
\[b = - 7.\]
\[2)\ 3x_{1} \cdot 3x_{2} = 9x_{1}x_{2} = 9 \cdot 1 = 9\]
\[c = 9.\]
\[Получаем\ уравнение:\ \]
\[x² - 7x + 9 = 0.\]