Question

resolva as equações do segundo grau usando a fórmula de Bhaskara 2x ao quadrado + 7x - 4 = 0​

Answer 1

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$2x^2+7x-4=0\\\\Coeficientes:\;a=2,\;b=7\;e\;c=-4\\\\\Delta=b^2-4ac\\\Delta=7^2-4\cdot2\cdot(-4)\\\Delta=49+32\\\Delta=81\\\\x=\dfrac{-b\pm\sqrt{\Delta}}{2a}\\\\x=\dfrac{-7\pm\sqrt{81}}{2\cdot2}\\\\x=\dfrac{-7\pm9}{4}\\\\x_1=\dfrac{-7+9}{4}=\dfrac{2}{4}=1/2\\\\x_2=\dfrac{-7-9}{4}=\dfrac{-16}{4}=-4$