Question

Como resolver :
calculo completo .

x²+ x -7= 5

Answer 1

x² + x - 7 = 5

x² + x - 7 - 5 = 0

x² + x - 12 = 0
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a = 1, b = 1, c = - 12

Δ = b² - 4 . a . c

Δ = 1² - 4 . 1 . (-12)

Δ = 1 + 48

Δ = 49
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x = (-b ± √Δ)/2a

x = (-1 ± √49)/2
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x' = (-1 + 7)/2

x' = 6/2

x' = 3
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x'' = (-1 - 7)/2

x'' = - 8/2

x'' = - 4


Forte abraço!