(For this lesson, the term
"radical" will refer only to "square root".)
When adding or subtracting radicals, you must use the
same concept as that of adding or subtracting "like" variables.
In other words, the
radicals must be the
same
before
you add (or subtract) them.
Example 1: 

1. Are the radicals the same? 
Answer: 
NO 
2. Can we simplify either
radical? 
Answer: 
Yes, can be simplified. 
3. Simplify the radical. 
Answer: 

4. Now, the radicals are the
same
and we can add. 
Answer: 

Example 2: 

