5 Points \(A , B\) and \(C\) have position vectors \(\left( \begin{array} { l } 1
2
3 \end{array} \right) , \left( \begin{array} { c } 2
- 1
5 \end{array} \right)\) and \(\left( \begin{array} { c } - 4
0
3 \end{array} \right)\) respectively.
- Find the exact distance between the midpoint of \(A B\) and the midpoint of \(B C\).
Point \(D\) has position vector \(\left( \begin{array} { c } x
- 6
z \end{array} \right)\) and the line \(C D\) is parallel to the line \(A B\). - Find all the possible pairs of \(x\) and \(z\).