it clicked to me during exam that R2 -> R2 - R3 = some const * direction vector of line.
so R3 -> (const) * (R2-R3) + R3 can give me any point. so since (1,0,0) passes through the line i set R3 = (1,0,0)
So opening along R3 gives gamma-c (forgive me if any sign mistake/conceptual error)
now how do i proceed?