Question

resposta da questão: x²+2x-11=0

Answer 1

$x^2+2x-11=0\\\\ \Delta=b^2-4\cdot a\cdot c\\ \Delta=2^2-4\cdot1\cdot(-11)\\ \Delta=4+44\\ \Delta=48\\\\ x=\dfrac{-b\pm\sqrt{\Delta}}{2a}=\dfrac{-2\pm\sqrt{48}}{2\cdot1}=\dfrac{-2\pm4\sqrt{11}}{2}=-1\pm2\sqrt{11}\\\\\ \Longrightarrow\begin{cases}x_1=-1+2\sqrt{11}\\x_2=-1-2\sqrt{11}\end{cases}$