TITLE: Simplifying an Expression further
QUESTION [5 upvotes]: I have trouble doing this and I'm not sure why are they the same and what are the steps I need to do to reach the simplified answer. 
For example ...
$\frac{-8}{\sqrt{128}}$ 
This is the same as 
$\frac{-1}{\sqrt{2}} $ 

I'm not sure how to reach the simplified expression from the earlier expression .. Can anyone help me ? Thanks !

REPLY [5 votes]: Here are the steps: $$\frac {-8}{\sqrt{128}}=$$Simplify the bottom fraction $$ \frac {-8}{8\sqrt{2}}$$ cancel out the 8's $$ \frac {-1}{\sqrt{2}}$$