The equation of the plane passing through the point $(2 , 1 , -1 )$ and the line of intersection of the planes $\overrightarrow{r}. (\overrightarrow{i}+\overrightarrow{3j}-\overrightarrow{k})=0$ and $\overrightarrow{r}. (\overrightarrow{j}+\overrightarrow{2k})=0$ is
