换元t=x+1/x 则x2+1/x2=t^2-2
6(t^2-2)+5t=38
6t^2+5t-50=0 解得t=5/2或-10/3
再解x+1/x=5/2或 -10/3即可
解得x=2 1/2 -3 -1/3