Solve for x in the following equation.

For this case we must find the value of "x" of the following equation:
[tex]x ^ 2-9 = 0[/tex]
So:
We add 9 to both sides of the equation:
[tex]x ^ 2-9 + 9 = 9\\x ^ 2 = 9[/tex]
We apply square root on both sides of the equation to eliminate the exponent on the left side:
[tex]x = \pm \sqrt {9}[/tex]
Thus, the solutions are:
[tex]x_ {1} = + 3\\x_ {2} = - 3[/tex]
ANswer:
[tex]x_ {1} = + 3\\x_ {2} = - 3[/tex]
Opcion C