As it has a maximum value the coefficient of x^2 will be negative
The vertex will be at (-8,2) so in vertex form it is
y = a(x + 8)^2 + 2
and as it passes through (-7,-1) we have:
-1 = a(-7+8)^2 + 2
-1 = a + 2 so a = -3
answer is y = -3(x + 8)^2 + 2
in standard form this is y = -3x^2 -48x - 190
