One question, 3 parts

A. Find an equation for the plane consisting of all points (x,y,z) that are equidistant from the points (-4,2,1) and (2,-4,3).

B. Find the points A on the line with symmetric equations x=y=z and B on that with equations x+1=y/2=z/3 such that |AB| is the shortest distance between the two lines. Hence compute the shortest distance.

C. Let L be the line of intersection of the two planes with equations x+2y-z=2 and 2x-y+4z=5. Find the point A on this line such that the distance from (0,0,0) to A is the shortest from 0 to L.

needdd urgent helppp cant find solutions to these types of problems anywhere!