2÷3÷7+4÷6÷14+14÷21÷494÷7÷9+8÷14÷18+28÷49÷63=_.

问题描述:

2÷3÷7+4÷6÷14+14÷21÷49
4÷7÷9+8÷14÷18+28÷49÷63
=______.

原式=

1
3
×
1
7
+4×
1
6
×
1
14
+14×
1
21
×
1
49
    
1
7
×
1
9
+8×
1
14
×
1
18
+28×
1
49
×
1
63
 

=
2
21
(1+
1
2
+
1
7
4
63
( 1+
1
2
+
1
7
)

=
3
2