Question

resolva as equações do 2 grau a)x^2 - 5x + 6 =0 B)X^2 - 81 = 0 C} X^2 + 2X - 8 = 0

Answer 1

Olá!!!

Resolução!!!


a) x² - 5x + 6 = 0


∆ = (-5)² - 4.1.6
∆ = 1

X = -(-5) ± √1/2.1

X = 5 ± 1/2

X' = 5 - 1/2 = 4/2 = 2

X" = 5 + 1/2 = 6/2 = 3


S={ 2, 3 }


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B) x² - 81 = 0

x² = 81
x = ± √81
x = ± 9

S={ -9, 9 }

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C) x² + 2x - 8 = 0

∆ = 2² - 4.1.(-8)
∆ = 4 + 32
∆ = 36

X = -2 ± √36/2.1

X = -2 ± 6/2

X' = -2 - 6/2 = -8/2 = -4

X" = -2 + 6/2 = 4/2 = 2


S={ -4, 2 }