6. \( \frac{x^{5}}{y} \div \frac{x}{y^{2}} \)

Step 1 ：\( \frac{x^{5}}{y} \div \frac{x}{y^{2}} = \frac{x^{5}}{y} \cdot \frac{y^{2}}{x} \)

Step 2 ：\( \frac{x^{5}}{y} \cdot \frac{y^{2}}{x} = \frac{x^{5} \cdot y^{2}}{y \cdot x} \)

Step 3 ：\( \frac{x^{5} \cdot y^{2}}{y \cdot x} = \frac{x^{4}y}{1} = x^{4}y \)