Let L be the line given by x = 2 - t, y = 1 + t, z = 1 + 2t. L intersects the plane 2x + y - z = 1 at the point P = (1,2,3). Find the parametric equations for the line through P which lies in the plane and is perpendicular to L.

Im lost here. I cant find an examples on how to do this problem. I have come up with this so far

x = 1 + at

y = 2 + bt

z = 3 + ct

but Im not sure that this is right.