- TeX source:
- \begin{array}{rclcll}\dfrac{27x^3+6x^2}{3x} &=& -\dfrac{3x+6}{27(x+2)} \cr\cr \dfrac{3x(9x^2+2x)}{3x} &=& -\dfrac{3(x+2)}{27(x+2)} \cr\cr 9x^2+2x &=& -\dfrac{1}{9} & \vert & +\dfrac{1}{9} \cr 9x^2+2x+\dfrac{1}{9} &=& 0 & \vert & :9 \cr x^2+\dfrac{2}{9}x+\dfrac{1}{81} &=& 0 &\vert& \text{p-q-Formel} \cr x_{1,2} &=& -\dfrac{1}{9} \pm \sqrt{\left(\dfrac{1}{9}\right)^2-\dfrac{1}{81}} \cr\cr x_{1,2} &=& -\dfrac{1}{9} \pm\sqrt{0} \cr\cr x_{1,2} &=& -\dfrac{1}{9} \;\in\;\mathbb{D} \cr\cr \mathbb{L} &=& \left\{-\dfrac{1}{9}\right\} \end{array}