\[ax^{2} - 16x + 3 = 0\]
\[x_{1} = 3:\]
\[9a - 48 + 3 = 0\]
\[9a = 45\]
\[a = 5.\]
\[Подставим\ и\ решим:\]
\[5x^{2} - 16x + 3 = 0\]
\[D_{1} = 64 - 15 = 49\]
\[x_{1} = \frac{8 + 7}{5} = 3;\]
\[x_{2} = \frac{8 - 7}{5} = \frac{1}{5} = 0,2.\]
\[Ответ:x_{2} = 0,2.\]