The given equation of the plane is

or , where

For reducing the given equation to normal form, we need to divide it by .

Then, we get,

Dividing both sides by – 1, we get

……(i)

The equation of a plane in normal form is

……(ii)

Where d is the distance of the plane from the origin

Comparing (i) and (ii)

Length of the perpendicular from the origin to the plane = d = 2 units.