Question

5X²+6x+8=0
conta montada pf ?

Answer 1

$5x^{2} +6x + 8 = 0$

Resolvendo por Bháskara:

$x = \dfrac{-b \pm \sqrt{b^2 -4*a*c}}{2*a}$

a=5, b=6, c=8

Δ=b²−4ac
Δ=(6)2−4*(5)*(8)
Δ=36−160
Δ= −124

$x = \dfrac{-b \pm \sqrt{\triangle}}{2*a} \\ \\ \\ x = \dfrac{-6 \pm \sqrt{-124}}{2*5} \\ \\ \\ x = \dfrac{-6 \pm \sqrt{124}.i}{10} \\ \\ \\ x = \dfrac{-6 \pm 2\sqrt{31}.i}{10} \\ \\ \\ x' = \dfrac{-6 + 2\sqrt{31}.i}{10} \\ \\ \\ x' = \dfrac{-3 + \sqrt{31}.i}{5} \\ \\ \\ x'' = \dfrac{-6 - 2\sqrt{31}.i}{10} \\ \\ \\ x'' = \dfrac{-3 - \sqrt{31}.i}{5}$

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S = { $\dfrac{-3 + \sqrt{31}\ . i}{5}, \ \ \dfrac{-3 - \sqrt{31}\ . i}{5}$ }