当-1当-1
当-1泪伤157,(y+1)/|y+1|-|y-2|/(y-2)+y/|y|=1-1+1=1
(y+1)/|y+1|-|y-2|/(y-2)+y/|y|=1-1+1=1
1
原式=(y+1)/(y+1)-[-(y-2)/(y-2)+(y/(-y)]=1+1-1=1