Răspuns:
Explicație pas cu pas:
2x² - 5x + 2 = 0
a = 2 ; b = - 5 ; c = 2
∆ = b² - 4ac = (- 5)² - 4 × 2 × 2 = 5² - 8 × 2 = 25 - 16 = 9 → ∃ x1 , x2 ∈ ℝ ; x1 ≠ x2
[tex]x_1 = \frac{ - b + \sqrt{ \triangle} }{2a} = \frac{ - ( - 5) + \sqrt{9} }{2 \times 2} = \frac{5 + 3}{4} = \frac{8}{4} = 2 \\ [/tex]
[tex]x_2 = \frac{ - b - \sqrt{ \triangle} }{2a} = \frac{ - ( - 5) - \sqrt{9} }{2 \times 2} = \frac{5 - 3}{4} = \frac{2 {}^{(2} }{4} = \frac{1}{2} \\ [/tex]
[tex]S = \{2; \frac{1}{2} \} \\ [/tex]
