5. Let ri = (3 -t, 1 + 3t, 1+ t) and 72 = (s -1, s + 1, 5s). [6] Determine whether the two lines are parallel, intersecting, or skew (not parallel and not intersecting). 6. Find an parametric equation of a line that is perpendicular to both lines ri = (3 + 2t, -1 + 4t, 2 -t) and 72 = (1 + 4s, 1 + 2s, -3 + 4s) and passes through their intersection. [8]