TeX source:
\begin{array}{rclcl} 357-2x^2 &=& -35 & \vert & -357 \cr -2x^2 &=& -392 & \vert & :(-2) \cr x^2 &=& 196 & \vert & \pm \sqrt{} \cr x &=& \pm \sqrt{196} \cr\cr x_1 &=& 14 \cr x_2 &=& -14 \cr \cr \mathbb{L} &=& \{-14; 14\} \end{array}