Question

A solução da equação abaixo será igual a:
a)2 e -2
b)4
c)2
d)não tem solução real
e)4 e -4​​

Answer 1

$\large\boxed{\begin{array}{l}\sf (x^2)^2-2x^2-8=0\\\sf\Delta=b^2-4ac\\\sf\Delta=(-2)^2-4\cdot1\cdot(-8)\\\sf\Delta=4+32\\\sf\Delta=36\\\sf x^2=\dfrac{-b\pm\sqrt{\Delta}}{2a}\\\sf x^2=\dfrac{-(-2)\pm\sqrt{36}}{2\cdot1}\\\sf x^2=\dfrac{2\pm6}{2}\\\sf x^2=\dfrac{2+6}{2}=\dfrac{8}{2}=4\\\sf x^2=4\\\sf x=\pm\sqrt{4}\\\sf x=\pm2\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~a}}}}\end{array}}$