Question

Determine if the parallel lines in each pair are distinct or
coincident.
a) [x, y, z] = [5, 1, 3] + s[2, 1, 7]
[x, y, z] = [2, 3, 9] + t [2, 1, 7]
b) [x, y, z] = [4, 1, 0] + s[3, -5, 6]
[x, y, z] = [1