Respuesta :

addd 4 to both sides
[tex]\sqrt{x+9}=5[/tex]
sqare both sides
x+9=25
minus 9 both sides
x=16

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

not extraneous
an extraneous root would be x=-34