Question 317295
The equation is in vertex form.
The vertex is ({{{-7}}},{{{9}}}).
The axis of symmetry is {{{x=-7}}}.
Since the coefficient of {{{x^2}}} is negative, the parabola opens downward, the y value at the vertex is a maximum.
{{{ymax=9}}}

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{{{drawing(300,300,-12,2,-2,12,blue(line(-7,-20,-7,20)),grid(1),circle(-7,9,.3),graph(300,300,-12,2,-2,12,-4(x+7)^2+9))}}}