The required plane is parallel to X - axis i.e. the normal of the plane is perpendicular to X - axis so, the component of the normal vector along X - axis is zero (0).

We know that the general equation of a plane is given by,

Ax + By + Cz + D=0, where ……… (1)

Here, A, B, C are the coordinates of a normal vector to the plane, while (x, y, z) are the co - ordinates of any point through which the plane passes.

Putting A=0 [∵ the component of the normal vector along X - axis is zero (0)] in the general equation i.e. in equation (1) of plane we get,

By + Cz + D=0, where ……… (2)

Hence, By + Cz + D=0 is the general equation of a plane parallel to X - axis.