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 planes is 1 . ∴|‌
d
√12+22+23
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‌
|=1⇒d=±3 So equation of required plane x−2y+2z±3=0