Question

X²-2×-15=0 calcule as raízes da equação

Answer 1

Resposta:

$x^{2} - 2x -15 = 0\\x1=-3 \\ou\\x2 = 5$

Explicação passo a passo:

$x^{2} - 2x -15 = 0\\\\x = \frac{-(-2) +-\sqrt{(-2^{2}) - 4 . 1.(-15) } }{2.1}\\\\x = \frac{2 +-\sqrt{(-2^{2}) - 4.(-15) } }{2}\\\\x = \frac{2 +-\sqrt{(-2^{2}) + 60 } }{2}\\\\x = \frac{2 +-\sqrt{4 + 60 } }{2}\\\\x = \frac{2 +-\sqrt{64} }{2}\\\\x = \frac{2 +-8}{2}$

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$x1 = \frac{2+8}{2} = \frac{10}{2} = 5\\\\x2 = \frac{2-8}{2} = \frac{-6}{2} = -3$

espero ter ajudado!!