Given the following vector equations of lines [math]l_1:\vec{r}=\left(2,4,1\right)+t\left(3,-1,1\right)[/math] and [math]l_2:\vec{r}=\left(1,4,4\right)+s\left(-6,2,-2\right)[/math], [br]a) Show that the lines are parallel and distinct,[br]b) Find a vector equation of the plane containing both lines.