Question 1079985
{{{-2x^2+40x+320}}}

{{{x^2-20x-160}}}

{{{x^2-20x+100-100-160}}}

{{{(x-10)^2-260}}}
Vertex at x=10


-


{{{-2*10^2+40*10+320}}}
{{{-200+400+320}}}
{{{200+320}}}
{{{highlight(520)}}}