We want to get rid of the square root sign somehow, so let's isolate that term.
Now, in order to 'undo' a root sign, we need to do the opposite to it, by squaring the term, but in order for it to remain the same, we need to square 4 as well.
Now, we can isolate the variable:
, and since we can't simplify this further, our final answer becomes:
or 
Now, in order to 'undo' a root sign, we need to do the opposite to it, by squaring the term, but in order for it to remain the same, we need to square 4 as well.
Now, we can isolate the variable: