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=1/2 13/18:5/18=2целых 3/5 3 13/18-15/18=2 16/18 11/18*2=1 2/9 13/18+5/6=28/18