Question

equação de segundo grau x²-3x-4=0

Answer 1

$x^2-3x-4=0 \\ a = 1, b = -3, c = -4 \\ \\ \Delta = b^2 - 4ac \\ \Delta = (-3)^2 - 4 . 1 . (-4) \\ \Delta = 9 + 16 \\ \Delta = 25 \\ \\ x = \frac{-b \pm \sqrt{\Delta} }{2a} \\ x = \frac{- (-3) \pm \sqrt{25}}{2.1} \\ x = \frac{3 \pm 5}{2} \\ \\ x = \frac{3 + 5}{2} \\ x = \frac{8}{2} = 4 \\ \\ x = \frac{3 - 5}{2} \\ x = \frac{-2}{2} = -1$