983.
1) 5/9+13/27= 3•5/3•9 + 13/27=
= 15/27+13/27= 28/27= 1 1/27
2) 3/8+5/24= 9/24+5/24=
= 14/24= 7/12
3) 5/12-13/72= 30/72-13/72=
= 17/72
4) 3/5-1/7= 21/35-5/35= 16/35
5) 5/12+1/60=25/60+1/60=
= 26/60= 13/30
6) 9/17-19/68= 36/68-19/68=
= 17/68= 1/4
7) 9/10+4/15=27/30+8/30=
= 35/30= 7/6= 1 1/6
8) 4/15-11/60= 16/60-11/60=
= 5/60= 1/12
984.
1) 3/4+1/4=1
2) 2/7+5/7=1
3) 1/6+5/6=1
4) 2/9+7/9=1
5) 1/10+9/10=1
6) 8/11+3/11=1