The equation of the perpendicular bisecting plane of the line segment joining $(-3, 3, 2), (9, 5, 4)$ is

mid-point of given point $=\left({\mathrm{x}}_1, {\mathrm{y}}_1, {\mathrm{z}}_1\right)=\left(3, 4, 3\right)$

$\mathrm{drs}=\left(\mathrm{a}, \mathrm{b}, \mathrm{c}\right)=\left(12, 2, 2\right)$

$\begin{array}{rcl}12\left(\mathrm{x}-3\right)+2\left(\mathrm{y}-4\right)+2\left(\mathrm{z}-3\right)& =& 0\\ 12\mathrm{x}-36+2\mathrm{y}-8+2\mathrm{z}-6& =& 0\\ 12\mathrm{x}+2\mathrm{y}+2\mathrm{z}-50& =& 0\\ 6\mathrm{x}+\mathrm{y}+3-25& =& 0\end{array}$