Dividing radicals

  10√2
--------
    √5

   10√2 √5
------------   {multiplied top and bottom by √5 to eliminating radical sign in denominator}
      √5 √5

  10√10
---------   {multiplied square roots on top and bottom}
     √25 

  10√10
---------   {evaluated √25 to be 5}
       5

= 2√10   {cancelled 10 and 5}

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