Isolate the radical on the left by adding 2 to both sides

          

          

Now square both sides of the equation:

          

When you square a square root, you take away the radical:

          

Divide both sides by 5:

          

          

But you MUST check square root equations because sometimes
an answer you get won't check in the original equation:

          

Substitute  for 

          

          

          

          

So the solution  checks.

Edwin