Question

Resolva a equação abaixo:
-3x elevado a 2 + 7x +20=0

Answer 1

-3x²+7x+20=0(-1)

3x²-7x-20=0

∆=b²-4ac

∆=(-7)²-4.3.(-20)

∆=49+240=289

x=(-b±√∆)/2a

$x = \frac{ - ( - 7)± \sqrt{289} }{2.3} \\ x = \frac{7±17}{6}$

$x' = \frac{7 + 17}{6} = \frac{24}{6} = 4 \\ x'' = \frac{7 - 17}{6} = - \frac{10}{6} = - \frac{5}{3}$