Question

Resolva a equação 2°grau???

-3x²+x+2=0

Answer 1

-3x² +x +2=0

3x² -x -2=0
a=3
b=-1
c=-2

Δ=b²-4ac
Δ=(-1)²-4(3)(-2)
Δ=1+24
Δ=25
√Δ=√25 = ±5

$x=- \frac{b\pm \sqrt{\triangle} }{2a} = \frac{-(-1)\pm \sqrt{25} }{2.3} = \frac{1\pm5}{6} \\ \\ x'= \frac{1+5}{6} = \frac{6}{6} =1 \\ \\ x"= \frac{1-5}{6} =- \frac{4}{6} =- \frac{2}{3}$

$S=\{- \frac{2}{3} ,1\}$