Answer:

Explanation:
To simplify:

First of all, let us write 18 and 162 as product of prime factors:

The pairs are underlined as above.
While taking roots, only one of the numbers from the pairs will be chosen.
Now, taking square roots.


So, the given expression becomes:
 
 
So, the answer is:
 or 18 StartRoot 2 EndRoot
 or 18 StartRoot 2 EndRoot