Question

resolva as equacoes de 2 grau a seguir
a) x²-x-6=0
b)x²+5x6=0
c)2x²-4x+2=0

Answer 1

a) x² - x - 6 = 0

delta = b² - 4.a.c

a = 1
b = -1
c = -6

delta = (-1)² - 4.1.(-6)
delta = 1 + 24
delta = 25

x = -b ± √delta/2.a

x = -(-1) ± √25/2.1

x = 1 ± 5/2

x = 1 - 5/2 = -4/2 = -2

x = 1 + 5/2 = 6/2 = 3

S={ -2, 3 }
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.
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b) x² + 5x + 6 = 0

a = 1
b = 5
c = 6

delta = 5² - 4.1.6
delta = 25 - 24
delta = 1

x = -5 ± √1/2.1

x = -5 ± 1/2

x = -5 - 1/2 = -6/2 = -3

x = -5 + 1/2 = -4/2 = -2

S={ -3, -2 }
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.
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c) 2x² - 4x + 2 = 0

a = 2
b = -4
c = 2

delta = (-4)² - 4.2.2
delta = 16 - 16
delta = 0

x = -(-4) ± √0/2.2

x = 4 ± 0/4 = 4/4 = 1

S={ 1 }



☆Espero ter ajudado!