Bonjour,
x + 3 + x - 4 = 0
2x - 1 = 0
2x = 0 + 1
2x = 1
x = 1/2 = 0.5
2x² - 5x = 0
Δ = b² - 4ac = (-5)² - 4 * 2 * 0 = 25
x1 = (- b - √Δ) / 2a = (5 - 5) / 2 * 2 = 0/4 = 0
x2 = (- b + √Δ) / 2a = (5 + 5) / 2 * 2 = 10/4 = 2.5
Les solutions sont x1 = 0 et x2 = 2.5
(x + 1)(x + 2) = 0
x + 1 = 0
x = -1
et
x + 2 = 0
x = -2
(3x - 5)(3x - 5) = 0
3x - 5 = 0
3x = 5
x = 5/3
