\[\boxed{\mathbf{144}.}\]
\[1)\ y = x^{2} - 4x + 1\]
\[x_{0} = \frac{4}{2} = 2;\ \]
\[\ y_{0} = 4 - 8 + 1 = - 3.\]
\[Ответ:y_{наим} = - 3\ при\ x = 2.\]
\[2)\ y = x^{2} + 6x - 3\]
\[x_{0} = - \frac{6}{2} = - 3;\ \ \]
\[y_{0} = 9 - 18 - 3 = - 12.\]
\[Ответ:y_{наим} = - 12\ при\ x = - 3.\]
\[3)\ y = - x^{2} + 2x + 3\]
\[x_{0} = \frac{2}{2} = 1;\ \ \]
\[y_{0} = - 1 + 2 + 3 = 4.\]
\[Ответ:y_{наиб} = 4\ при\ x = 1.\]
\[4)\ y = - x^{2} - 2x + 5\]
\[x_{0} = - \frac{2}{2} = - 1;\ \ \]
\[y_{0} = - 1 + 2 + 5 = 6.\]
\[Ответ:y_{наиб} = 6\ при\ x = - 1.\]
\[5)\ y = - 2x^{2} + 4x + 1\]
\[x_{0} = \frac{4}{4} = 1;\ \ \]
\[y_{0} = - 2 + 4 + 1 = 3.\]
\[Ответ:y_{наиб} = 3\ при\ x = 1.\]
\[6)\ y = 2x^{2} + 6x - 1\]
\[x_{0} = - \frac{6}{4} = - 1,5;\ \ \]
\[y_{0} = 2 \cdot 2,25 - 9 - 1 =\]
\[= 4,5 - 10 = - 5,5.\]
\[Ответ:y_{наим} = - 5,5\ при\]
\[\ x = - 1,5.\]