I'm having trouble comparing primal solution and dual problem from the semidefinite program
$$\begin{array}{ll} \text{minimize} & 2x_1\\ \text{subject to} & \begin{pmatrix} 0 & 5x_1 & 0 \\ 5 x_1 & 3x_2 & 0 \\ 0 & 0 & 4 x_1 \end{pmatrix} \succeq 0\end{array}$$
I can't seem to find how to compare two solutions.