To evaluate the algebraic expression \(\frac{x+y}{x-y}-x^{2}\) for \(x=3\) and \(y=4\), we substitute the values of \(x\) and \(y\) into the expression.
First, let's substitute the values:
\(\frac{3+4}{3-4}-3^{2}\)
Simplifying the expression further, we have:
\(\frac{7}{-1}-9\)
Dividing 7 by -1, we get:
\(-7-9\)
Combining like terms, we have:
\(-16\)
Therefore, when \(x=3\) and \(y=4\), the expression \(\frac{x+y}{x-y}-x^{2}\) evaluates to \(-16\).