The distance of the point (1, 3, −7) from the plane passing through the point $(1, −1, −1),$ having normal perpendicular to both the lines $\large\frac{x-1}{1}=\frac{y+2}{-2}=\frac{z-4}{3}$ and $\large\frac{x-2}{2}=\frac{y-1}{-1}=\frac{z+7}{-1}$, is:
