Two identical spheres each of mass 2kg and radius 50cm are fixed at...

Using parallel axis theorem, we can write total moment of inertia as, $I = \left(\dfrac{2}{5}m{R}^{2} + m{d}^{2}\right) \times 2$

$⇒ I = 2\left(\dfrac{2}{5} \times 2 \times {\left(\dfrac{1}{2}\right)}^{2} + 2 \times {\left(\dfrac{3}{4}\right)}^{2}\right) = \dfrac{53}{20}kg{m}^{2}$

Therefore, $x = 53$.