Determine whether the following objects intersect or not. If they intersect at a single point, describe the intersection (could be a point, a line, etc.) (a) The lines given by r = (4 + t, -21,1 + 3t) and = x = 1-t, y = 6 + 2t, z = 3 + 2t. (b) The lines given by x= 1 + 2s, y = 7 - 3s, z= 6 + s and x = -9 +6s, y = 22 - 9s, z = 1+ 3s. = (c) The plane 2x - 2y + 3z = 2 and the line r= (3,1, 1 – t). (d) The planes x + y + z = -1 and x - y - z = 1.