令t=(x^2-2)/x则方程化为：t+2/t=3即t^2-3t+2=0(t-1)(t-2)=0t=1,2t=1时,(x^2-2)/x=1,即x^2-x-2=0,得（x-2)(x+1)=0,x=2,-1t=2时,(x^2-2)/x=2,即x^2-2x-2=0,得x=1+√3,1-√3经验算,共有以上4个根....