A plane E is perpendicular to the two planes 2 x-2 y+z=0 and x-y+2 z=4, and passes through the point P(1,-1,1). If the distance of the plane E from…

A plane $\displaystyle E$ is perpendicular to the two planes $\displaystyle 2 x-2 y+z=0$ and $\displaystyle x-y+2 z=4$, and passes through the point $\displaystyle P(1,-1,1)$. If the distance of the plane $\displaystyle E$ from the point $\displaystyle Q(a, a, 2)$ is $\displaystyle 3 \sqrt{2}$, then $\displaystyle (P Q)^2$ is equal to