\(\left(x^2+\frac{4}{x^2}+1\right)^2=\left(x^2-\frac{4}{x^2}-1\right)^2\)
=> \(x^2+\frac{4}{x^2}+1=x^2-\frac{4}{x^2}-1\)
=> \(\left(x^2-x^2\right)+\left(\frac{4}{x^2}+\frac{4}{x^2}\right)=-1-1\)
=> \(\frac{8}{x^2}=-2\)
=> \(8=-2x^2\)
\(=>x^2=-4\)
=> x = rỗng
=> \(x^2=-4\)