Achar a distância entre as retas r_{1} e r_{2}, nos casos: r_{1}:\left\{\begin{array}{l}x=\lambda+1, \\\ y=\lambda+2, \\\ z=-2 \lambda-2\end{array} \quad\right. e r_{2}:\left\{\begin{array}{l}x=\lambda, \\\ y=1+3 \lambda, \\\ z=-4 \lambda\end{array} \quad\right.