Respuesta :

X would be 4
Because if we input 4 into wherever it says x, we get:
[tex] \sqrt{x} + 5 = \sqrt{x + 45} \\ \sqrt{4} + 5 = \sqrt{4 + 45} \\ 2 \: + \: 5 \: = \sqrt{49} \\ 7 \: = 7[/tex]