How to solve this question?

Answer: -3
Step-by-step explanation:
The axis of symettry is basically what cuts the parabola perfectly in half. In this case draw a horizontal line right through -3 on the x-axis
Answer:
[tex]x=-3[/tex]
Step-by-step explanation:
A parabola's axis of symmetry is located at the line [tex]x=h[/tex] and essentially divides the parabola in half. The vertex is [tex](-3,4)[/tex] so the axis of symmetry is located at the line [tex]x=-3[/tex]