Answer:
See below in bold.
Step-by-step explanation:
y = 3(x + 2) (x + 6)
3(x + 2) (x + 6) = 0
x = -2, -6.
The x -intercepts are (-2,0) and (-6, 0).
Convert to vertex form:
y=3(x + 2) (x + 6)
y = 3(x^2 + 8x + 12)
y = 3(x^2 + 8x) + 36
y = 3[(x + 4)^2 - 16] + 36
y = 3(x + 4)^2 - 12.
So the vertex is at (-4, -12) and
the axis of symmetry x = -4.