Sorry for such vague title.

Anyway, I am doing some math evaluation test when I ran across these bad boys.

For question #1, I have no idea where to begin.

For question #2, I forgot how to deal with absolute values.

For question #3:

So, Sub that into the other equation and we get

but we do not get any nice roots, and all the options for the questions are rational.

If some one can show me how to solve these, I would appreciate it