Question

me ajudem na equação biquadrada×4-×2-12=0​

Answer 1

$x^4-x^2-12=0\\\\\boxed{x^2=y}\\\\x^2\cdot x^2-x^2-12=0\\\\y^2-y-12=0\\\\a=1,\;b=-1\;e\;c=-12\\\\\Delta=b^2-4ac\\\Delta=(-1)^2-4\cdot1\cdot(-12)\\\Delta=1+48\\\Delta=49\\\\\\y=\dfrac{-b\pm\sqrt{\Delta}}{2a}\\\\\\y=\dfrac{-(-1)\pm\sqrt{49}}{2\cdot1}\\\\\\y=\dfrac{1\pm7}{2}\\\\\\y_1=\dfrac{1+7}{2}=\dfrac{8}{2}=4\\\\\\y_2=\dfrac{1-7}{2}=\dfrac{-6}{2}=-3\\\\\\y=x^2\\\\y_1=x_1^2\\4=x^2\\2^2=x^2\\\boxed{x=2}\\\\y_2=x_2^2\\-3=x^2\\\boxed{Nao\;existe\;x_2.}\\\\\\\\\boxed{\boxed{\boxed{Resposta:\;x=2}}}$