\[y = x^{2} - 10x + 20 \Longrightarrow ветви\ \ \]
\[вверх;\ \]
\[\text{\ x}_{0} = \frac{10}{2} = 5,\ \ \ \]
\[y_{0} = 25 - 50 + 20 =\]
\[= - 5\ \Longrightarrow (5;\ - 5).\]