A pair of lines in R³ are said to be skew if they are neither parallel nor intersecting. Determine whether the following pairs of lines are parallel, intersecting, or skew. If the lines intersect, determine the point(s) of intersection.

r(t) = (4 + 5t, -2t, 1 + 3t);
R(s) = (10s, 6 + 4s, 4 + 6s)