TeX Quellcode:

\begin{array}{rclcl} 3x &=& \dfrac{15}{4+x} &\vert& \cdot(4+x) \cr 3x\cdot(4+x) &=& 15 &\vert& \text{ausmultiplizieren} \cr 12x+3x^2 &=& 15 &\vert& -12x-3x^3 \cr 0 &=& -3x^2-12x+15 &\vert& :(-3) \cr 0 &=& x^2+4x-5 &\vert& \text{p-q-Formel} \cr x_{1,2} &=& -\dfrac{4}{2}\pm\sqrt{\left(\dfrac{4}{2}\right)^2-(-5)} \cr x_{1,2} &=& -2\pm 3 \cr\cr x_1 &=& -2+3 = 1 \cr x_2 &=& -2-3 = -5 \end{array}