Answer
$ \displaystyle \frac{x}{y}$
Work Step by Step
Apply rule $\displaystyle \quad \frac{a^{m}}{a^{n}}=a^{m-n}$
$\displaystyle \frac{x^{2}y^{3}}{xy^{4}}=\frac{x^{2}}{x}\cdot\frac{y^{3}}{y^{4}}\quad$.
$=x^{2-1}y^{3-4}$
$=x^{1}y^{-1}\quad$
Apply rule $\displaystyle \quad a^{-n}=\frac{1}{a^{n}}$
$=\displaystyle x \cdot \frac{1}{y}
\\=\displaystyle \frac{x}{y}$