Answer:

Explanation:
Given its parameters, we know that this quadratic equation represents a parabola with arms pointing down, and with a maximum value at the point of its vertex.
The equation of its axis of symmetry will be a vertical line that goes through that vertex.
Recall that vertical lines have the form:
.
It is essential then that we find the x coordinate of such vertex to complete the general equation form of this vertical axis.
We use the definition for the x value of the vertex of a parabola of the form:

In our case where

the x-value of the vertex becomes:

Therefore, the equation for the axis of symmetry of the parabola is:
