I Am Going Ask My teacher. I just screenshot it.
Answer:
8
Step-by-step explanation:
the pair of triangles is showing a dilations with a scale factor of 2
6/3=2
so it gives us 4 as the before answer and 4x2=8 so x=8
The vertex of the parabola is at (5,3) and its focal length is 8/4 = 2.
Since it opens to the right, the directrix will be a vertical line 2 units to the left of the vertex, so its equation will be x=(5-2), or x=3
Either 1, or 2, smart ppl help!