You have the point (6, -4) and the line x=-2 (in blue)
As you reflect the point across line x=2, the distance between initial point and the line and the distance of point after reflection and the line in coordinates x needs to be the same.
The distance in x from the initial point and the line is 8 units.
Then, after reflection the coordinates of point are ( -10 , -4)
Now to reflection across the line x=4: (line x=4 in purple)
The distance in x from the initial point and the line is 14 units.
Then, after reflection the coordinates of point are (18, -4):
