Challenge 380: Line Location
Where is the mirror in this laser beam set-up?
A laser is positioned at the point (1, 1) on the x-y plane.
A flat mirror is placed at right angles to the plane standing on top of a straight line L, and the laser beam is reflected by this mirror.
The beam hits the mirror at the point (4, -3) and also passes through through the point (-20, 15).
Find the equation of L.