Write the rational expressic \[ \frac{r^{2}-s^{2}}{r+s} \]

To simplify the expression \(\frac{r^{2}-s^{2}}{r+s}\), we can recognize that the numerator \(r^{2} - s^{2}\) is a difference of squares. The difference of squares can be factored as follows: \[ r^{2} - s^{2} = (r - s)(r + s) \] Now, substituting this back into the original expression gives us: \[ \frac{(r - s)(r + s)}{r + s} \] If \(r + s \neq 0\), we can cancel \(r + s\) from the numerator and denominator, resulting in: \[ r - s \] So, the simplified rational expression is: \[ r - s \]