−12.4(x2+34x−12x−408)−12.4(x2+22x−408)=0−12.4x2−272.8x+5059.2=0
\begin{lgathered}12.4 {x}^{2} + 272.8x \\ - 5059.2 = 0 \div 12.4 \\ {x}^{2} + 22x - 408 = 0\end{lgathered}12.4x2+272.8x−5059.2=0÷12.4x2+22x−408=0
\begin{lgathered}d = 484 + 1632 = 2116 = {46}^{2} \\ x1 = \frac{ - 22 + 46}{2} = \frac{24}{2} = 12\end{lgathered}d=484+1632=2116=462x1=2−22+46=224=12
x2 = \frac{ - 22 - 46}{2} = - \frac{68}{2} = - 36x2=2−22−46=−268=−36