# How do you simplify #-(xy^-1)/(9z^-2)# and write it using only positive exponents?

##### 1 Answer

Apr 8, 2018

#### Explanation:

Recall the law of indices about negative indices:

When you move the base and the index from the numerator to the denominator or from the denominator to the numerator, the sign changes.

The negative sign in the front does not change.