- TeX source:
- \begin{array}{rclcl} \dfrac{1}{2}(14x+x)x &=& -\dfrac{-21x^2+x}{6}+\dfrac{x^2+30}{3}+812{,}5 & \vert & \cdot 6 \cr\cr 3x\cdot(15x) &=& 21x^2-x+2x^2+60+4.875 \cr\cr 45x^2 &=& 23x^2-x+4.935 & \vert & -45x^2 \cr\cr 0 &=& -22x^2-x+4.935 & \vert & :(-22) \cr\cr 0 &=& x^2+\dfrac{1}{22}x-\dfrac{4.935}{22} \cr\cr x_{1,2} &=& -\dfrac{1}{44} \pm \sqrt{\dfrac{1}{1.936}+\dfrac{4.935}{22}} \cr\cr x_1 &=& \dfrac{329}{22} \cr\cr x_2 &=& -15 \cr \cr \mathbb{L} &=& \left\{-15;\dfrac{329}{22}\right\} \end{array}