计算:(要求写出计算过程)(1)5114×45+6115×56+7116×67(2)1-12×{1-13×[1-14×(1-15)]}(3)[1-(112+115)×4]÷(310÷925)(4)2008×112÷113-10025÷120.-数学

76)×
6
7

=(40+1)+(50+1)+(60+1),
=150+3,
=153;

(2)1-
1
2
×{1-
1
3
×[1-
1
4
×(1-
1
5
)]},
=1-
1
2
×{1-
1
3
×[1-
1
4
×
4
5
]},
=1-
1
2
×{1-
1
3
×[1-
1
5
]},
=1-
1
2
×{1-
1
3
×
4
5
},
=1-
1
2
×{1-
4
15
},
=1-
1
2
×
11
15

=1-
11
30

=
19
30


(3)[1-(
1
12
+
1
15
)×4]÷(
3
10
÷
9
25
),
=[1-
3
20
×4]÷(
3
10
×
25
9
),
=[1-
3
5
5
6

=