\[y = - 5x^{2} - 20x + 6 \Longrightarrow ветви\ \]
\[вниз;\]
\[x_{0} = \frac{20}{- 10} = - 2,\ \ \ \ \ \ \ \]
\[y_{0} = - 5 \cdot 4 + 40 + 6 =\]
\[= 26 \Longrightarrow \ \ ( - 2;\ \ 26).\]