Answer
$\frac{61}{36y}$.
Work Step by Step
In order to add or subtract fractions, we start by making a common denominator (bottom of the fraction). Thus, we multiply 5/9y by 4/4 and 9/4y by 9/9 to obtain:
$\frac{81}{36y}$-($\frac{20}{36y}$)=$\frac{61}{36y}$.
