(6,8-5 5/9):(2 13/30-2 1/12)*3,6

(6,8-5 5/9):(2 13/30-2 1/12)*3,6= 12 4/5
1)  6 8/10-5 5/9=6 72/90-5 50/90=1 22/90=1 11/45  общ.множ=90
2)  2 13/30-2 1/12=2 26/60-2 5/60=21/60=7/20  общ.множ = 60
3)1 11/45:7/20= 56/45:7/20=56/45*20/7=32/9=3  5/9  сокращаем крест накрест
4)  3 5/9*3 6/10=32/9*36/10=64/5=12 8/10=12 4/5