Réponse :
Explications étape par étape
Bonjour,
Résoudre :
(-x² + x + 6)(-2x² + 3x - 1) = 0
-x² + x + 6 = 0 ou -2x² + 3x - 1 = 0
Δ = 1² - 4 * (-1) * 6 = 1 + 24 = 25
√Δ = √25 = 5
x1 = (-1 - 5)/(2 * (-1)) = -6/-2 = 3
x2 = (-1 + 5)/(2 * (-1)) = 4/-2 = -2
Δ = 3² - 4 * (-2) * (-1) = 9 - 8 = 1
√Δ = √1 = 1
x1 = (-3 - 1)/(2 * (-2)) = -4/-4 = 1
x2 = (-3 + 1)/(2 * (-2)) = -2/-4 = 1/2
S = {-2 ; 1/2 ; 1 ; 3}
(x - 1)/(x + 1) = (2x - 5)/(x - 1)
x + 1 ≠ 0
x ≠ -1
x - 1 ≠ 0
x ≠ 1
(x - 1)² = (2x - 5)(x + 1)
x² - 2x + 1 = 2x² + 2x - 5x - 5
2x² - x² - 3x + 2x - 5 - 1 = 0
x² - x - 6 = 0
Δ = (-1)² - 4 * 1 * (-6) = 1 + 24 = 25
√Δ = √25 = 5
x1 = (1 - 5)/2 = -4/2 = -2
x2 = (1 + 5)/2 = 6/2 = 3
S = {-2 ; 3} et ≠ {-1 ; 1}
