SOLUTION
We want to find the solution of the equation
[tex]x^2=64[/tex]This becomes
[tex]\begin{gathered} x^2=64 \\ we\text{ move the square to the other side it becomes square root, we have} \\ x=\sqrt{64}\text{ the square root sign attracts }\pm,\text{ so we have } \\ x=\pm\sqrt{64} \\ x=\pm8 \end{gathered}[/tex]Hence the answer is
[tex]\pm8[/tex]Note that square root of 64 is 8