For this case we have the following rational expression:

What we must do for this case, is to factor the numerator and the denominator.
We have then:

Then, canceling similar terms we have:

Then, the function is not defined for the values that make the denominator zero.
We have then:

And on the other hand, a zero of the function is:
Answer:
a zero of the function is:
the function is not defined for the value:
