Question

3.用简单的方法计算下面各题：不能直接写得数!快急

Answer 1

1.9/17+8/17+5/12=17/17+5/12=12/12+5/12=17/12

2.7/15-4/15-2/25=3/15-2/25=5/25-2/25=3/25

3.2/11+9/11+5/7=1+5/7=12/7

4.7/10+13/10+4/9+5/9=3