\[y = 11 + \sqrt{5x^{2} - 4x - 12}\]
\[имеет\ y_{\min}\text{\ \ \ }при\text{\ \ }\]
\[5x^{2} - 4x - 12 = 0\]
\[D = 16 + 240 = 256\]
\[x_{1},_{2} = \frac{4 \pm 16}{10} = 2;\ \ - 1,2\]
\[y_{\min} = 11\]
\[Ответ:\ \ \ y_{\min} = 11\ \ при\ \ x = 2;\]
\[\ \ x = - 1,2.\]