Answer
$\displaystyle \frac{x-5+y}{3}$
Work Step by Step
To subtract rational expressions with the same denominator,
subtract numerators and place the difference over the common denominator.
If possible, factor and simplify the result.
---
$\displaystyle \frac{x}{3}-\frac{5-y}{3}=\frac{x-(5-y)}{3}$
... a common error here is forgetting to place the second numerator in parentheses...
$=\displaystyle \frac{x-5+y}{3}$
