What is the average rate of change of $f(x)$ from $x_{1}=-9$ to $x_{2}=4$ ? Please write your answer as an integer or simplified fraction.
\[
f(x)=-2 x-5
\]

Step 1 ：Given the function \(f(x)=-2 x-5\), we are asked to find the average rate of change from \(x_{1}=-9\) to \(x_{2}=4\).

Step 2 ：The average rate of change of a function \(f(x)\) from \(x_{1}\) to \(x_{2}\) is given by the formula: \[\frac{f(x_{2}) - f(x_{1})}{x_{2} - x_{1}}\]

Step 3 ：Substitute \(x_{1}=-9\) and \(x_{2}=4\) into the function \(f(x)=-2 x-5\) and then use the formula to calculate the average rate of change.

Step 4 ：The average rate of change of the function \(f(x)=-2 x-5\) from \(x_{1}=-9\) to \(x_{2}=4\) is -2.0.

Step 5 ：Final Answer: The average rate of change of \(f(x)\) from \(x_{1}=-9\) to \(x_{2}=4\) is \(\boxed{-2}\).