Question

Resolva as seguintes Equações do 2° Grau e complete usando a Fórmula De bháskara
A) 2x ao Quadrado+2x-12=0
B) 2x Ao quadrado-x-1=0
C) -x ao quadrado +7x-12=0

Answer 1

Resposta:

Explicação passo-a-passo:

irei utilizar o $\beta$ para representar o Δ e facilitar minha escrita aqui

$A) 2x^{2} +2x-12 = 0\\\\\beta = b^2-(4ac)\\\beta= 2^2-(4*2*-12)\\\beta = 4 + 96\\\beta = 100\\\\x' =( -2 + \sqrt{100} )/2*2\\x' =( -2+10)/4\\x' = 8/4\\x' = 2\\\\\\\\x'' =( -2 - \sqrt{100} )/2*2\\x'' =( -2-10)/4\\x'' = -12/4\\x'' = -3$

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$B) 2x^{2} -x-1=0\\\\\beta= -1^2-(4*2*-1)\\\beta =-1+8\\\beta = 7\\\\x'=(1+\sqrt{7} )/4\\x''=(1-\sqrt{7} )/4$

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$C) -x+7x-12=0\\\\\beta = 7^2-(4*-1*-12)\\\beta =49-48\\\beta =1\\\\x'=(-7+\sqrt{1} )/(2*-1)\\x'= (-7+1)/-2\\x' =-6/-2\\x'=3\\\\x''=(-7-\sqrt{1} )/(2*-1)\\x'' = 4$