#### Answer

$\frac{3\sqrt y}{2y}$

#### Work Step by Step

To rationalize we must get rid of the square root in the denominator. We can do this by multiplying $\sqrt 16y$ with the numerator and the denominator.
$\frac{2\sqrt 9}{\sqrt 16y}\times\frac{\sqrt 16y}{\sqrt 16y}=\frac{2\sqrt 144y}{16y}=\frac{3\sqrt y}{2y}$