You didn't repond on the value of the other equation but the second equation which is
[tex]\begin{gathered} x^2=324 \\ \text{square root both side} \\ \sqrt{x^2}=\sqrt{324} \\ x=18\text{ or -18} \\ \text{Therefore, the equation x}^2=324\text{ has 2 solution.} \end{gathered}[/tex]