Explicație pas cu pas:
b) x² + 2x - 8 = 0
Δ = 4 + 32 = 36
[tex]x1 = \frac{ - 2 + \sqrt{36} }{2} = \frac{ - 2 + 6}{2} = \frac{4}{2} = 2[/tex]
[tex]x2 = \frac{ - 2 - 6}{2} = \frac{ - 8}{2} = - 4[/tex]
e) x² + 4x - 12 = 0
Δ = 16 + 48 = 64
[tex]x1 = \frac{ - 4 + \sqrt{64} }{2} = \frac{ - 4 + 8}{2} = 2[/tex]
[tex]x2 = \frac{ - 4 - 8}{2} = - 6[/tex]
h) x² - 10x + 16 = 0
Δ = 100 - 64 = 36
[tex]x1 = \frac{10 + \sqrt{36} }{2} = \frac{10 + 6}{2} = \frac{16}{2} = 8[/tex]
[tex]x2 = \frac{10 - 6}{2} = \frac{4}{2} = 2[/tex]
b) x² + x - 6 = 0
Δ = 1 + 24 = 25
[tex]x1 = \frac{ - 1 + \sqrt{25} }{2} = \frac{ - 1 + 5}{2} = \frac{4}{2} = 2[/tex]
[tex]x2 = \frac{ - 1 - 5}{2} = \frac{ - 6}{2} = - 3 [/tex]
e) x² - 6x + 8 = 0
Δ = 36 - 32 = 4
[tex]x1 = \frac{6 + \sqrt{4} }{2} = \frac{6 + 2}{2} = \frac{8}{2} = 4[/tex]
[tex]x2 = \frac{6 - 4}{2} = \frac{2}{2} = 1[/tex]
h) x² + 2x - 24 = 0
Δ = 4 + 96 = 100
[tex]x1 = \frac{ - 2 + \sqrt{100} }{2} = \frac{ - 2 + 10}{2} = \frac{8}{2} = 4[/tex]
[tex]x2 = \frac{ - 2 - 10}{2} = \frac{ - 12}{2} = - 6[/tex]
