5 9/10-2 7/10(5 5/12-3 17/36)+2 2/3•1 1/2=
5 9/10-2 7/10(2 15/36-17/36)+8/3•3/2=
5 9/10-2 7/10•1 34/36+4=5 9/10-27/10•35/18+4=
5 9/10-21/4+4=5 9/10-5 1/4+4=5 18/20-5 5/20+4=13/20+4=4 13/20
5 9/10-2 7/10(5 5/12-3 17/36)+2 2/3•1 1/2=
5 9/10-2 7/10(2 15/36-17/36)+8/3•3/2=
5 9/10-2 7/10•1 34/36+4=5 9/10-27/10•35/18+4=
5 9/10-21/4+4=5 9/10-5 1/4+4=5 18/20-5 5/20+4=13/20+4=4 13/20