TeX source:
\begin{array}{rclll} \dfrac{3x+4}{x^4 -5} &=& 0 & \vert & \cdot \left(x^4-5\right) \cr\cr 3x+4 &=& 0 & \vert & -4 \cr\cr 3x &=& -4 & \vert & :3 \cr\cr x &=& -\dfrac43 \in \mathbb{D} \cr\cr \end{array}