3/7 + 4/9=
17/18-11/12=
7/9+4/15=
1/8+4/9=
8/9-7/8=
7/16+1/6=
9/14+3/7-1/28=
9/11-2/5=
13/15-2/3=
5/6+2/9=
1/6+1/4-1/8=
13/16+9/32=
20/21+4/7=
10/21+9/14=
1/3-1/6-1/4=
3/28+5/14