Answer
$z(z-2)$
Work Step by Step
We are given the denominators $z-2$ and $z$.
In order to find the least common denominator, we must factor each denominator.
$z-2$ cannot be simplified further
$z$ cannot be simplified further
Next, we multiply together all distinct factors from each denominator, with each factor raised to the greatest power that occurs in any denominator.
$LCD=z\times(z-2)=z(z-2)$