Question

3X ao quadrado menos 9x menos 2 igual a 0

Answer 1

$3x^{2}+9x-2 =0 \\ \\ a=3 \\ b=9\\ c=-2\\ \\ \Delta = b^{2}-4.a.c \\ \\ x = \frac{-b \pm \sqrt{\Delta}}{2.a}\\ \\ [tex]\Delta = 9^{2} - 4.3.(-2) \\ \Delta = 81 + 24 \\ \Delta = 105$
$x = \frac{-9 \pm \sqrt{105}}{2.3} \\ \\ \\ x' = \frac{-9+\sqrt{105}}{2.3} \\ \\ x' \cong \frac{-9+10,25}{6} \\ \\ x' \cong \frac{1,25}{6} \\ \\ \\ x' \cong 0,2083 \\ \\ \\ x'' = \frac{-9 -\sqrt{105}}{2.3} \\ \\ x'' \cong \frac{-9 -10,25}{6} \\ \\ x'' \cong \frac{-19,25}{6} \\ \\ \\ x'' \cong -3,2083$