Question

5x²-x=-3x+2x²+8 equação do 2° grau

Answer 1

$5x^2 -x = -3x + 2x^2 + 8 \\ \\ 5x^2 - x + 3x - 2x^2 - 8 = 0 \\ \\ 3x^2 +2x - 8 = 0$

Δ=b²−4ac
Δ=(2)2−4⋅(3)⋅(−8)
Δ=4+96
Δ=100

$x = \dfrac{-b \pm \sqrt{\triangle}}{2a} \\ \\ x = \dfrac{-2 \pm \sqrt{100}}{2 * 3} \\ \\ x = \dfrac{-2 \pm 10}{6} \\ \\ x' = \dfrac{-2 +10}{6} \\ \\ x' = \dfrac{8}{6} \\ \\ x' = \dfrac{4}{3}$


$x'' = \dfrac{-2 - 10}{6} \\ \\ x'' = \dfrac{-12}{6} \\ \\ x'' = -2$


S = {$\dfrac{4}{3} , \ - 2$}