Question

-x²-5x+6=0
Mais esse

Answer 1

$\large\boxed{\begin{array}{l} \rm - x^{2} - 5x + 6 = 0 \\ \rm \Delta = b {}^{2} - 4ac \\ \Delta = ( - 5) {}^{2} - 4 \cdot( - 1) \cdot6 \\\Delta = 25 + 24 \\ \Delta = 49 \\ \\ \rm x = \dfrac{ - b \pm \sqrt{\Delta} }{2 a} \\ \\ \rm{x = \dfrac{ - ( - 5) \pm \sqrt{49} }{2 \cdot (- 1)} } \\ \\ \rm x = \dfrac{5 \pm7}{ - 2} \begin{cases} \rm{x _{1} = \dfrac{5 + 7}{ - 2} = \dfrac{12}{ - 2} = - 6} \\ \\ \rm{x _{2} = \dfrac{5 - 7}{2} = \dfrac{ - 2}{ - 2} = 1}\end{cases} \end{array}}$