4 14/39:2=170/39*1/2=85/39=2 7/39

2 7/39-1 5/52=2 28/156-1 15/156=

1 13/156=1 1/12

21,2212:20,02=1,06

1 1/12-1,06=1 1/12-1 3/50=1 25/300-1 18/300=7/300