1.(x+2)/(x^2-3x+2)>=1(x+2)/(x^2-3x+2)-1>=0(x+2-x^2+3x-2)/(x-1)(x-2)>=0(-x^2+4x)/(x-1)(x-2)>=0x(x-4)/(x-1)(x-2)<=0解得到0<=x<1或22.甲:(2X+1)/X<=0,得到-1/2<=X<0乙:0<2X+1<1,得到-1/2所以,甲是乙的必要而不充分条件.选择B
