Given -

First Plane is

2x – y + 4z = 5

Multiply both sides by 2.5, we get -

5x - 2.5y + 10z = 12.5 …(1)

Second Plane is

5x – 2.5y + 10z = 6 …(2)

Clearly, the direction ratios of normals of both the plane (1) and (2) are same.

Hence, Both the given planes are parallel.