2 3/4+2/4=?; 2 3/7-3/7=?; 5 5/6+2/6=?; 3 -1/3=?; 9 7/10+6/10=?; 16/17+11 15/17=?;

2 3/4+2/4=3 1/4; 2 3/7-3/7=2; 5 5/6+2/6=6 1/6; 3 -1/3=2 2/3; 9 7/10+6/10=10 3/10; 16/17+11 15/17=12 14/17