Given two lines in space, either they are parallel, they intersect, or they are skew (lie in parallel planes). Determine whether the lines below, taken two at a time, are parallel, intersect, or are skew. If they intersect, find the point of intersection. Otherwise, find the distance between the two lines

.L1:

x=1t,

y=12t,

z=1t,

L2:

x=12s,

y=14s,

z=12s,

L3:

x=1+r,

y=1+r,

z=1r,