Given the equation:
[tex]x^2=9[/tex]To determine the value of x, we take the square root of both sides.
Note that before the square root of a number, we always have the plus/minus sign.
[tex]\begin{gathered} \sqrt{x^2}=\pm\sqrt{9} \\ x=\pm3 \end{gathered}[/tex]Therefore, the values of x that can make the equation true are 3 and -3.
Check
[tex]\begin{gathered} 3^2=9 \\ (-3)^2=9 \end{gathered}[/tex]