2x/(x+1)>1
2x/(x+1)-1>0
2x/(x+1) - (x+1)/(x+1) > 0
[2x-(x+1)] / (x+1) > 0
(x-1) / (x+1) > 0
(x-1)(x+1)>0
所以 x>1 或者 x