If a solid sphere of mass \( 5 \, \text{kg} \) and a disc of mass \( 4 \, \text{kg} \) have the same radius. Then the ratio of moment of inertia of the disc about a tangent in its plane to the moment of inertia of the sphere about its tangent will be \( \dfrac{x}{7} \). The value of \( x \) is _______.
