Respuesta :

JcAlmighty
The answer is 4.

Square root of 2x plus 1 = 3:
[tex] \sqrt{2x+1} =3[/tex]

Square both sides:
[tex]( \sqrt{2x+1} )^{2} =3^{2} \\ \\ 2x+1=9 \\ 2x = 9 - 1 \\ 2x =8 \\ x = 8:2 \\ x =4 [/tex]