Solution 2 of 2
Rather than use shortcuts I have given a lot of detail. This is so that you can see where some of the shortcuts come from.
You are looking for squared values/variables that can be 'taken outside' the square root.
Demonstrating a property by example:
Suppose we had
Write as :
You can cancel some out at this stage. I will do it later.
'Extracting from the root' we have:
This is the same as:
Now we deal with the 11: