TeX source:
\begin{array}{rclcl} u_1 = x^2 &=& 8 &\vert& \pm\sqrt{} \cr x_{1,2} &=& \pm\sqrt{8} \cr\cr u_2 = x^2 &=& -9 &\vert& \pm\sqrt{} \cr x_{3,4} &=& \pm\sqrt{-9}\end{array}