There is no way we can tell from that what goes under the square 
roots and what does not.  Always put parentheses around what goes 
under the square root like this:

F(x)=sqrt(x+4)+sqrt(4)+x

or

F(x)=sqrt(x)+4+sqrt(4+x)

or

F(x)=sqrt(x+4)+sqrt(4+x)

or

F(x)=sqrt(x)+4+sqrt(4)+x

All those are different.  If you'll tell me which one of those
you mean in the thank-you note form below, I'll get back to
you.

Edwin