3(7-2 5/11)-11 3/11+5 7/11
3(7-2 5/11)-11 3/11+5 7/11=3*4 6/11-11 3/11+5 7/11=13 7/11-11 3/11+5 7/11=2 4/11+5 7/11=7 11/11=8