ANSWER
D) 10
Step-by-step explanation
We want to solve the radical equation,

Square both sides,

Expand brackets on right hand side,

Rewrite in general quadratic equation form,

Factor to obtain,

Apply the zero product principle to get,

We put n=2 into the equation to get,


This statement is false, hence 2 is an extraneous solution
We put n=10, to get



This is true, hence the only solution is
