1.) Find the equation of the plane containing A(3,2,1) and the line x=1+t, y= 2-t, z = 3+2t

I know that there are two positional vectors, 3i+2j+k and i+2j+3k, and I know I have a vector equation..but what do I do? I thought of using dot product, but I don't know what I should dot..

2.) The perpendicular from a point to a line minimizes the distance from the point to that line.Use quadratic theory to find th ecoordinates of the foot of the perpendicular from (1,1,2) to the line with equations x=1+t, y=2-t, z=3+t

I really do not know how to do this one..

Thank you for your help, really would want to know how to solve these two questions, thanks so so much for your efforts in advance!