7 Show that the straight lines with equations \(\mathbf { r } = \left( \begin{array} { l } 4
2
4 \end{array} \right) + \lambda \left( \begin{array} { l } 3
0
1 \end{array} \right)\) and \(\mathbf { r } = \left( \begin{array} { r } - 1
4
9 \end{array} \right) + \mu \left( \begin{array} { r } - 1
1
3 \end{array} \right)\) meet.
Find their point of intersection.