Respuesta :

x² - 81 = 0
x² = 81
x = √81
x = 9

Answer:

x=9 x=-9

Step-by-step explanation:

[tex]x^{2}[/tex]-81=0

  +81 +81

[tex]x^{2}[/tex]=81

[tex]\sqrt{x^{2} }[/tex]=[tex]\sqrt{81}[/tex]

x=±9

the person above me was right just didn't finish putting it all in.