Question

resolva a equação de segundo grau
x2 - 4 x - 12 = 0
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Answer 1

Resposta:

$x^{2} -4x-12=0\\ \\ coeficientes:\\ a=1\\ b=-4\\ c=-12\\ \\ delta=b^{2} -4.a.c\\ \\ delta=(-4)^{2} -4.1.(-12)\\ \\ delta=16-(-48)\\ \\ delta=16+48\\ \\ delta=64$

$x=\frac{-b+-\sqrt{delta} }{2.a} \\ \\ x=\frac{-(-4)+-\sqrt{64} }{2.1} \\ \\ x=\frac{4+-8}{2} \\ \\ x'=\frac{4+8}{2} =\frac{12}{2} =6\\ \\ x''=\frac{4-8}{2} =\frac{-4}{2} =-2\\ \\ \\ S\left \{ {{6;-2} {}} \}$