问题 选择题 已知实数x满足x2+1x2+x-1x=4,则x-1x的值是( )A.-2B.1C.-1或2D.-2或1 答案 x2+1x2-2+x-1x-2=0∴(x-1x)2+(x-1x)-2=0解得x-1x=-2或1.故选D