9. Expressed as a radical expression, the fraction \( \frac{x^{1 / 3} x^{1 / 2}}{x^{-1}} \) is \( \begin{array}{ll}\text { (1) } \frac{1}{\sqrt[6]{x}} & \text { (3) } \sqrt[11]{x^{6}} \\ \text { (2) } \frac{1}{\sqrt[11]{x^{6}}} & \text { (4) } \sqrt[6]{x^{11}}\end{array} \)

To simplify the expression \( \frac{x^{1 / 3} x^{1 / 2}}{x^{-1}} \), first combine the exponents in the numerator: \[ x^{1/3} \cdot x^{1/2} = x^{(1/3 + 1/2)} = x^{(2/6 + 3/6)} = x^{5/6}. \] Now, we divide by \( x^{-1} \): \[ \frac{x^{5/6}}{x^{-1}} = x^{5/6 - (-1)} = x^{5/6 + 1} = x^{5/6 + 6/6} = x^{11/6}. \] Expressing \( x^{11/6} \) in radical form gives: \[ x^{11/6} = \sqrt[6]{x^{11}}. \] Thus, the expression in radical form is \(\sqrt[6]{x^{11}}\), which corresponds to option (4). So the correct answer is \( \sqrt[6]{x^{11}} \).