下面个题怎样简便就怎样算：7/8+4/7+1/8 1/6+3/5+2/5+1/6 9/5—2/7—5/7 5/9—3/8

7/8+4/7+1/8=7/8+1/8+4/7=1+4/7=11/7
1/6+3/5+2/5+1/6=1/6+1/6+(3/5+2/5)=2/6+1=4/3
9/5-2/7-5/7=9/5-(2/7+5/7)=9/5-1=4/5
5/9-3/8+4/9+3/8=5/9+4/9-3/8+3/8=5/9+4/9=1
2/5+2/3-2/5=2/5-2/5+2/3=1+2/3=5/3