(1)(
1
2 +
3
4 )×(
1
2 -
1
3 ),
=
5
4 ×
1
6 ,
=
5
24 ;
(2)
7
5 ×
1
11 +1.4÷
11
10 ,
=
7
5 ×
1
11 +
7
5 ×
10
11 ,
=(
1
11 +
10
11 )×
7
5 ,
=1×
7
5 ,
=
7
5 ;
(3)[
3
5 -(
3
4 -
2
3 )]÷4,
=[
3
5 -
1
12 ]÷4,
=
31
60 ×
1
4 ,
=
31
240 ;
(4)(
3
4 +
5
12 )×12,
=
3
4 ×12+
5
12 ×12,
=9+5,
=14;
(5)(12×
5
6 -
17
4 )÷
1
4 ,
=(10-
17
4 )×4,
=10×4-
17
4 ×4,
=40-17,
=23;
(6)
7
12 ×49+50×
5
12 ,
=
7
12 ×49+49×
5
12 +
5
12 ,
=49×(
7
12 +
5
12 )+
5
12 ,
=49×1+
5
12 ,
=49+
5
12 ,
=49
5
12 .