Question

Dada a equacao 2x² - 6 = x - 4 qual x' e x" sao as raizes reais determine x' + x"

Answer 1

2x² - 6 = x - 4
2x² - 6 - x + 4 = 0
2x² - x - 2 = 0

Δ = b² - 4ac ⇒ Δ = (-1)² - 4.2.(-2) ⇒ Δ = 1 + 16 ⇒ Δ = 17

x = (-b ± √Δ)/2a ⇒  x = (-(-1) ± √17)/2.2 ⇒  x = (1 ± √17)/4

x' = (1 + √17)/4

x'' = (1 - √17)/4


S = { (1 - √17)/4  ;  (1 + √17)/4 }