Answer
$\dfrac{4}{x}$
Work Step by Step
RECALL:
$\dfrac{\frac{a}{b}}{\frac{c}{d}}=\dfrac{a}{b} \cdot \dfrac{d}{c}$
Use the rule above to have:
$\\=\dfrac{4}{x-1} \cdot \dfrac{x-1}{x}$
Cancel the common factors to have:
$\require{cancel}
\\=\dfrac{4}{\cancel{x-1}} \cdot \dfrac{\cancel{x-1}}{x}
\\=\dfrac{4}{x}$
