Respuesta :

Answer:

X = 9 or x = -9

Step-by-step explanation:

We want to solve the quadratic equation

[tex] {x}^{2} - 4 = 77[/tex]

We shall use the square root method

Let us add 4 to both sides to get:

[tex] {x}^{2} - 4 + 4 = 77 + 4[/tex]

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

We take square to get:

[tex]x = \pm \sqrt{81} [/tex]

[tex]x = \pm9[/tex]

The solution is x=9 or -9

Answer:

B (x=9 or x=-9)

Step-by-step explanation:

Correct on EDGE