Ration expressions cause excluded values wherever the denominator equals zero.
So, for any expression like
[tex]h(x)=\dfrac{f(x)}{g(x)}[/tex]
-5 is an excluded value if [tex]g(-5)=0[/tex]
For example, the simplest one would be
[tex]h(x) = \dfrac{1}{x+5}[/tex]
In fact, if you try to evaluate this function at -5, you'd have
[tex]h(-5)=\dfrac{1}{5+5}=\dfrac{1}{0}[/tex]
which is undefined, and thus you can't evaluate the function, and thus -5 is an excluded value.
