2-(x+3)/(x+1)>=0
(2x+2-x-3)/(x+1)>=0
(x-1)(x+1)>=0
x+1在分母,不等于0
所以A={x|x>=1,x<-1}
(x-a-1)(2a-x)>0
[x-(a+1)](x-2a)<0
a<1,所以a+1>2a
所以2aB含于A
则2a所以a<=-2,a>=1/2
所以a<=-2,1/2<=a<1