An equation of a plane parallel to the plane x - 2y + 2z - 5 = 0 and at a unit distance from the origin is
x - 2y + 2z - 3 = 0
Equation of plane parallel to x - 2y + 2z - 5 = 0 is x - 2y + 2z + k = 0 ...(1)
|k|√1+4+4=1 ⇒|k|=3 ⇒k=±3 ∴x−2y+2z−3=0