(1)
9
13 ×(
2
3 -
1
9 ),
=
9
13 ×
2
3 -
9
13 ×
1
9 ,
=
6
13 -
1
13 ,
=
5
13 ;
(2)
3
4 ×
2
7 +
1
4 ×
2
7 ,
=(
3
4 +
1
4 )×
2
7 ,
=1×
2
7 ,
=
2
7 ;
(3)15×
7
8 ÷
7
8 ÷35,
=15×
7
8 ×
8
7 ×
1
35 ,
=
3
7 ;
(4)97×
7
10 +
7
10 +
7
10 ×2,
=(97+l+2)×
7
10 ,
=100×
7
10 ,
=70;