1) (12 1/18-7 5/18)-2 17/18=4 14/18-2 17/18=1 15/18
2) 16 4/9-(3 7/9+8 8/9)=16 4/9-12 6/9=3 7/9
3) (11 2/7-5 4/7)+(1 3/7+4 6/7)=5 5/7+6 2/7=12
4) (6 8/11+2 5/11)-(10 3/11-5 9/11)=9 2/11-4 5/11=4 8/11
1) (12 1/18-7 5/18)-2 17/18=4 14/18-2 17/18=1 15/18
2) 16 4/9-(3 7/9+8 8/9)=16 4/9-12 6/9=3 7/9
3) (11 2/7-5 4/7)+(1 3/7+4 6/7)=5 5/7+6 2/7=12
4) (6 8/11+2 5/11)-(10 3/11-5 9/11)=9 2/11-4 5/11=4 8/11