Question

look at this graph:
what is the equation of the axis of symmetry?

Explanation:

Step1: Identify x-intercepts

The parabola crosses the x-axis at $x=0$ and $x=-7$.

Step2: Calculate midpoint of intercepts

The axis of symmetry is the midpoint of the two x-intercepts. The formula for the midpoint of two points $x_1$ and $x_2$ is $\frac{x_1+x_2}{2}$.
$\frac{0 + (-7)}{2} = \frac{-7}{2} = -3.5$

Answer:

$x = -3.5$ (or $x=-\frac{7}{2}$)