(1) 12.5×
1
7 ×0.56 =1;
(2) 9
5
7 -3
4
9 +2
4
9 -8
3
7 ,
=(9
5
7 -8
3
7 )-(3
4
9 -2
4
9 ),
=1
2
7 -1,
=
2
7 ;
(3) 2
5
7 -(
3
5 -
2
7 ) ,
=2
5
7 -
3
5 +
2
7 ,
=27+
2
7 -
3
5 ,
=3 -
3
5 ,
=2
2
5 ;
(4)7800×8÷36×108÷26,
=7800×8×
1
36 ×108×
1
26 ,
=7200;
(5)
1
6 +
1
12 +
1
20 +
1
30 ,
=
1
2 -
1
3 +
1
3 -
1
4 +
1
4 -
1
5 +
1
5 -
1
6 ,
=
1
2 -
1
6 ,
=
1
3 ;
(6) 1
1
9 +2
1
90 +3
1
900 ,
=(1+2+3)+(
1
9 +
1
90 +
1
900 ),
=6+
37
300 ,
=6
37
300 .