X^2+1/(X^2)+1/X+X=0

问题描述:

X^2+1/(X^2)+1/X+X=0

等式两边乘以x^2
x^4+1+x+x^3=0
x(x^3+1)+x^3+1=0
(x^3+1)(x+1)=0
x=-1