We know that, distance between two parallel planes:

Ax + By + Cz + D₁=0…… (1) and Ax + By + Cz + D₂=0…… (2) is given by,

Here, the two parallel planes are given as,

2x + 2y - z + 2=0 …………… (3)

and 4x + 4y - 2z + 5=0 i.e. 2x + 2y - z + =0 ………… (4)

Comparing equation (3) with equation (1) and equation (4) with equation (2) we get,

A=2, B=2, C= - 1, D₁=2 and D₂=.

So, the distance between the given two parallel planes are,

Hence, the distance between the parallel planes 2x + 2y - z + 2=0 and 4x + 4y - 6z + = is .