Step-by-step explanation:
any quadratic equation has the form
y = ax² + bx + c
so, we can see in our case
a = 1
b = 8
c = 7
the x value of the vertex is indeed camcorders by
x = -b/(2a) = -8/2 = -4
the corresponding y we get then
y = (-4)² + 8×-4 + 7 = 16 - 32 + 7 = -9
the vertex = (-4, -9).
the y- intercept is simply the point with x = 0 (and the corresponding y value).
which is c, because
y = 0² + 8×0 + 7 = 7
the y-intercept = (0, 7)
