Question

quais são as raizes da equação (x+5)²=9

Answer 1

(x+5)² = 9

x² + 2 . x . 5 + 5² = 9

x² + 10x + 25 = 9

x² + 10x + 25 - 9

x² + 10x + 16 = 0

a = 1

b = 10

c = 16

∆ = b² - 4 . a . c

∆ = 10² - 4 . 1 . 16

∆ = 100 - 64

∆ = 36

x = - b ± √∆

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2a

x' = - 10 - 6

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2 . 1

x' = - 16

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2

x' = - 8

x" = - 10 + 6

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2 . 1

x" = - 4

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2

x" = - 2