k(x+2)-k^2＞x+1
kx-x＞k^2-2k+1
(k-1)x＞(k-1)^2
1.当k-1=0,k=1时,x无解
2.当k-1＞0,k＞1时,x＞k-1
3.当k-1＜0,k＜1时,x＜k-1