a(x-1)-x-1+2a>0ax-a-x-1+2a>0(a-1)x+a-1>0 (a-1)x>-(a-1)因为x<-1所以讨论就可以啦2提 同理
a(X-1)＞X+1-2aaX-a＞X+1-2aX＞(1-a)/(a-1)X＜-14X-3a＞-1X＞(3a-1)/42(X-1)+3＞5X＞2(3a-1)/4=2a=3
