Moment of inertia of a rod,

$\overline{)\begin{array}{rcl}{\mathbf{I}}& {\mathbf{=}}& \frac{\mathbf{M}{\mathbf{L}}^{\mathbf{2}}}{\mathbf{12}}\end{array}}$

Moment of inertia of a point mass,

$\overline{)\begin{array}{rcl}{\mathbf{I}}& {\mathbf{=}}& {{\mathbf{MX}}}^{{\mathbf{2}}}\end{array}}$

Rod's moment of inertia,

What is the moment of inertia I of this assembly about the axis through which it is pivoted?

Express the moment of inertia in terms of m_{r}, m_{1}, m_{2}, and x. Keep in mind that the length of the rod is 2x, not x.