The question is attached (#1, parts a and b). I have no idea how to do part b and as for part a. I don't remember what I did but when I try to think about the problem: I see that to find that the lines do not intersect I need to find that there is an inconsistence between the s[7,-1,-2] and t[1,1,2] slopes. (Is that what they're called?) Also, to find that they're not parallel I need some matrix to have only nonzero rows but I am confused as to which matrix I look at for the parallel one. Is it the same as the one where I looked for the inconsistence?

If I'm unclear, please tell me.

Any help would be GREATLY appreciated!

Thanks in advance!