Question

下面各题怎样算简便就怎样算4/7+1/6-4/7 2-7/9-2/9 3/5+7/8+2/5 7/9-{1/9+1/3}

1/4+{2/5+3/4} 5/6-3/10+1/6-7/10

Answer 1

4/7+1/6-4/7
=1/6 + 4/7 -4/7
=1/6

2-7/9-2/9
=2-（7/9+2/9）
=2-1
=1

3/5+7/8+2/5
= 3/5+2/5+7/8
=1+7/8
=1又7/8

7/9-{1/9+1/3}
=7/9 -1/9 -1/3
=6/9 -1/3
=2/3 -1/3
=1/3

1/4+{2/5+3/4}
=1/4+3/4+2/5
=1+2/5
=1又2/5

5/6-3/10+1/6-7/10
=5/6 +1/6-(3/10+7/10)
=1-1
=0