Question 255366
I don't know how you got to that.
But for this problem I will assume you are right.
you take the sqrt(23/2) and get a number for it.
sqrt(11.5)
put it in your calculator

so there are two answers
3+ that and 
3- that

You have to learn how to write in math language. 
sqrt(23/2)
{{{sqrt(23/2)}}}