Since square roots are never negative we must in the
end be sure that our answer cannot be negative.  But
first:



Multiply what's under the radicals.



Simplify



The largest perfect square that will divide 
into 50 is 25, so write  as 



We can take out the square root of 25 as 5
in front of the radical:



The index of a square root is understood
to be 2, like this:



And we divide the exponents of x and y by
the index 2, getting 2 and 5.  Since there
is no remainder, we will have no x's or
y's left under the radical, but only the 2.



Now we have just one more thing to take
care of.  Since we know that the answer
cannot be negative, we look at the factors:
The  is never negative.
The  is never negative
The  is never negative.

However the  just might be negative,
because if  were a negative number,
then  would also be a negative
number.  So we must put absolute value
bars around the  to keep it from causing
the expression to be negative, so the
final answer is 



Edwin