Resposta :
[tex]x_V=-\dfrac{b}{2a}=-\dfrac{20}{2\cdot10}=-\dfrac{20}{20}=-1\\\\
\boxed{x_V=-1}\\\\\\
y_V=-\dfrac{\Delta}{4a}=-\dfrac{b^2-4\cdot a\cdot c}{4\cdot10}=-\dfrac{20^2-4\cdot10\cdot40}{40}=-\dfrac{400-1600}{40}=-\dfrac{-1200}{40}\\\\
=\dfrac{1200}{40}=30\\\\
\boxed{y_V=30}[/tex]