1-2/5-3/10。
=10/10-4/10-3/10
=(10-4-3)/10
=3/10
8/11+3/13-8/11。
=(8+3-8)/11
=3/11
1/5+1/3。
=3/15+5/15
=8/15
1/4+1/8。
=2/8+1/8
=3/8
1-2/5-3/10
=10/10-4/10-3/10
=(10-4-3)/10
=3/10
8/11+3/13-8/11
=8/11-8/11+3/13
=0+3/13
=3/13
1/5+1/3
=3/15+5/15
=8/15
1/4+1/8
=2/8+1/8
=3/8
1-2/5-3/10。
=10/10-4/10-3/10
=3/10
8/11+3/13-8/11。
=8/11-8/11+3/13
=0+3/13
=3/13
1/5+1/3。
=3/15+5/15
=8/15
1/4+1/8。
=2/8+1/8
=3/8
10/10-4/10-3/10=(10-4-3)/10=3/10
8/11-8/11+3/13=0+3/13=3/13
3/15+5/15=8/15
2/8+1/8=3/8