(2x-1)/(x+1)<0两边除以2(x-1/2)(x+1)<0相除小于0则一正一负因为-1/2<1所以x-1/2所以x-1/2为负,x+1为正x-1/2<0,x,1/2x+1>0,x.-1所以-1
原式=(2x^2+x-1)/x=(2x-1)(x+1)/x当x<0,(2x-1)(x+1)>0,x<-1或x>1/2,得x<-1当x>0,(2x-1)(x+1)<0,-1综上x<-1或0
利用结论,f(x)/g(x)<0等价于f(x)*g(x)<0,即(2X-1)*(X+1)<0,再利用一元二次不等式解即可