explain why the line (x,y,z) = (4,-5,2) + t (2,1,0) is parallel to xy plane

 (x,y,z) = (4,-5,2)  + t (2,1,0)

 here (4,-5,2) is the point and direction is 2i + j + 0k 

as the cofficient of direction of z axis is 0 

so the line is parallel to xy plane 

explain why the line (x,y,z) = (4,-5,2)  + t (2,1,0)  is parallel to xy plane