Question

resolva as seguintes equações do segundo grau completas.

a) x² - 7x +6= 0
b) 2x² - 3x + 1 = 0​

Answer 1

a) x² - 7x + 6 = 0

a = 1

b = - 7

c = 6

∆ = b² - 4 . a . c

∆ = (-7)² - 4 . 1 . 6

∆ = 49 - 24

∆ = 25

x = - b ± √∆

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2a

x' = -(-7) - 5

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2 . 1

x' = 7 - 5

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2

x' = 2

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2

x' = 1

x" = -(-7) + 5

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2 . 1

x" = 7 + 5

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2

x" = 12

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2

x" = 6

b) 2x² - 3x + 1 = 0

∆ = b² - 4 . a . c

∆ = (-3)² - 4 . 2 . 1

∆ = 9 - 8

∆ = 1

x = - b ± √∆

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2a

x' = -(-3) - 1

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2 . 2

x' = 3 - 1

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4

x' = 2 (÷2)

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4 (÷2)

x' = 1

--

2

x" = -(-3) + 1

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2 . 2

x" = 3 + 1

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4

x" = 4

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4

x" = 2