Since, we know that the equation of plane passing through a point A and perpendicular to vector n is (r−a)n=0 where, a is the position vector of point and n is the normal vector. Given, A=(2,1−3), n=3
^
i
−
^
j
+2
^
k
⇒a=2
^
i
+
^
j
−3
^
k
and r=x‌hat‌i+y‌hat‌j+z‌hat‌k ∴(r.a).n=0