Answer:

Explanation:
First, we can expand the right side of this equation.



Then, we can move the 15 to the left side.

Now, the equation is in a form where we can complete the square for x. Remember that anything we add to one side, we also have to add to the other side.



Finally, we can move the 16 to the right side.

The equation of the parabola is now in vertex form:
,
where
is the vertex of the parabola.
In the equation we just solved for (
), we can identify the following:
Therefore, the vertex of the parabola is:
