Problem 4. Find the parametric equations for the following lines and planes:
(1) the line through (2,1,0) and perpendicular to both i + j and j + k;
(2) the line of intersection of the planes x + 2y+3z = 1 and x - y + z = 1;
(3) the plane through the point (1,-1,-1) and parallel to the plane 5x - y - z = 6;
(4) the plane through the points (2,1,2), (3, -8,6) and (-2, -3, 1);