Answer:
x = - 8 and (- 8, 0 )
Step-by-step explanation:
Given a quadratic in standard form
y = ax² + bx + c ( a ≠ 0 )
Then the equation of the axis of symmetry which is also the x- coordinate of the vertex is
x = -
y = x² + 16x + 64 ← is in standard form, with
a = 1 and b = 16, then
x = - = - 8
Equation of axis of symmetry is x = - 8
Substitute x = - 8 into the quadratic and evaluate for y
y = (- 8)² + 16(- 8) + 64 = 64 - 128 + 64 = 0
vertex = (- 8, 0 )