Question

5. Resolva a equação do 2° grau completa em R:

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Answer 1

Resposta:

$x {}^{2} - 4x - 12 = 0 \\ a = 1 \: \: \: \: b = - 4 \: \: \: \: c = - 12 \\ \\∆ = b {}^{2} - 4 \times a \times c \\∆ = ( - 4) {}^{2} - 4 \times 1 \times - 12 \\ ∆ = 16 +48 \\∆ = 64 \\ \\ x = \frac{ - b + - \sqrt{64} }{2 \times a} \\ x = \frac{4 + -8 }{2} \\ x1 = \frac{4 + 8}{2} \\ x1 = \frac{12}{2} \\ x1 = 6 \\ x2 = \frac{4 - 8}{2} \\ x2 = \frac{ - 4}{2} \\ x2 = - 2$