Question

Does anyone know this and if it is extraneous or not?

Answer 1

Addd 4 to both sides
$\sqrt{x+9}=5$
sqare both sides
x+9=25
minus 9 both sides
x=16

plug it in for x and see
$\sqrt{16+9}-4=1$
$\sqrt{25}-4=1$
$5-4=1$
1=1
true

not extraneous
an extraneous root would be x=-34