Instead of solving your problem, I'll solve one exactly in every
detail like your problem.  That is to prevent students from ignoring 
the work we do here and submitting only our answers.

So I'll do this one step by step which is exactly like your problem.



Isolate the square root term:



Square both sides:









;  

; 

We must always check problems for extraneous roots when we
have squared both sides:

Check x=9









So 9 is a solution:

Check x=16









So 16 is also a solution.

Now do your problem exactly like this one.

Edwin