Răspuns:
Explicație pas cu pas:
x² + 9x + 14 = 0
a = 1 ; b = 9 ; c = 14
∆ = b² - 4ac = 9² - 4 × 1 × 14 = 81 - 56 = 25 > 0 ⟹ ∃ x1 , x2 ∈ ℝ ; x1 ≠ x2
[tex]x_1 = \frac{ - b + \sqrt{ \triangle} }{2a} = \frac{ - 9 + \sqrt{25} }{2} = \frac{ - 9 + 5}{2} = \frac{ - 4}{2} = - 2 \\ [/tex]
[tex]x_2 = \frac{ - b - \sqrt{ \triangle} }{2a} = \frac{ - 9 - \sqrt{25} }{2} = \frac{ - 9 - 5}{2} = \frac{ - 14}{2} = - 7 \\ [/tex]
