\textbf{136.} Using rotation of axes with appropriate scaling, the distance from the focus to the center of the conic section $x^2 + \sqrt{3}\,xy = \dfrac{3}{2}$ is:
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\hfill (1) $\sqrt{3}$ \hfill (2) $\sqrt{3}$ \hfill (3) $2$ \hfill (4) $3$ \hfill
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