Réponses

  • Utilisateur Brainly
2014-09-15T18:48:50+02:00
Par exemple : f(x) = x³ - 4x² - 7x + 10 = 0

x³ - x² - 3x² + 3x - 10x + 10 = 0
(x³ - x²) - (3x² - 3x) - (10x - 10) = 0
x²(x - 1) - 3x(x - 1) - 10(x - 1) = 0
(x - 1)(x² - 3x - 10) = 0

x - 1 = 0
x = 1

x² - 3x - 10 = 0

Δ = b² - 4ac
Δ = 9 + 40
Δ = 49

\boxed{\boxed{x_1_,_2= \frac{-b\pm\sqrt\Delta}{2a} }} \\  \\  \\  \\ x_1= \frac{3-7}{2} =-2 \\  \\ x_2= \frac{3+7}{2} =5

S= {- 2 ; 1 ; 5}