13/18*36/13, 13/18:5/18, 3 13/18-15/18, 1 1/18*2 2/19, 13/18+5/6, 13/18+5/27, 13/18-5/11

13/18*36/13=2;//// 13/18:5/18=13/18*18/5=13/5=2 3/5;///, 3 13/18-15/18=2 31/18-15/18=2 16/18=2 8/9;//// , 1 1/18*2 2/19=19/18*40/19=20/9=2 2/9;///, 13/18+5/6=13/18+15/18=28/18=14/9=1 5/9;///, 13/18+5/27=39/54+10/54=49/54;////, 13/18-5/11=143/198-90/198=53/198