Given equation of a plane is x - 2y + 2z - 5 = 0
So, Equation of parallel plane is given by x - 2y + 2z + d = 0
Now, it is given that distance from origin to the parallel plane is 1. ∴∣∣12+22+22d∣∣=1⇒d=±3
So equation of required plane x−2y+2z±3=0