Given an equation of the parabola:

We have to find the vertex and the x-intercept of the parabola.
It is known that the vertex of the parabola is equal to -b/2a.
Here, a = 1, b = 8, c = 16. So,

At x = -4, the y-coordinate is:

Thus, the vertex is (-4, 0).
Now, we know that the x-intercept can be obtained by setting y = 0.

Thus, there is only one x-intercept -4.