#### Answer

$\frac{5x}{3y^2}$

#### Work Step by Step

$45x^2y=\underline3\times\underline3\times5\times \underline x\times x\times \underline y$
$27xy^3=\underline3\times\underline3\times3\times \underline x\times \underline y\times y\times y$
GCF=$3\times3\times x\times y=9xy$
$\frac{45x^2y}{27xy^3}=\frac{45x^2y\div9xy}{27xy^3\div9xy}=\frac{5x}{3y^2}$