712÷[34-(1112-12)]0.65×6.4-6.5×0.64+65×9%[459-(225+0.64)÷3125+56]×4.51-2+3-4+5-6+…+2009-2010+2011110×13+113×16+116×19+…+134×37112+216+3112+…+9190+101110.-数学

题文

7
12
÷[
3
4
-(
11
12
-
1
2
)]
0.65×6.4-6.5×0.64+65×9%
[4
5
9
-(2
2
5
+0.64)÷3
1
25
+
5
6
]×4.5
1-2+3-4+5-6+…+2009-2010+2011
1
10×13
+
1
13×16
+
1
16×19
+…+
1
34×37

1
1
2
+2
1
6
+3
1
12
+…+9
1
90
+10
1
110
题型:解答题  难度:中档

答案

(1)
7
12
÷[
3
4
-(
11
12
-
1
2
)],
=
7
12
÷[
3
4
-
5
12
],
=
7
12
÷
1
3

=
7
12
×3,
=
7
4


(2)0.65×6.4-6.5×0.64+65×9%,
=0.65×6.4-6.5×0.64+65×0.09,
=0.65×6.4-0.65×6.4+0.65×9,
=0.65×(6.4-6.4+9),
=0.65×9,
=0.65×(10-1),
=6.5-0.65,
=5.85;