[tex]C)\:\pm3\sqrt{3}[/tex]
1) Note that this quadratic equation is an incomplete one since the coefficient b is equal to zero.
2) So, we can solve it using another method rather than the quadratic equation.
[tex]\begin{gathered} x^2=27 \\ x_1=\sqrt{27},\:x_2=-\sqrt{27} \\ x_1=3\sqrt{3},\:x_2=-3\sqrt{3} \\ \end{gathered}[/tex]
Thus, the answer is C
