问题 解答题
我能用简便方法计算.
86×
2
85
2
3
+
3
4
+
1
6
)÷
1
12
1
2
×37.5%+
4
5
×
3
8
+
7
10
÷
8
3
答案

(1)86×

2
85

=(85+1)×

2
85

=85×

2
85
+1×
2
85

=2+

2
85

=2

2
85

(2)(

2
3
+
3
4
+
1
6
)÷
1
12

=(

2
3
+
3
4
+
1
6
)×12,

=

2
3
×12+
3
4
×12+
1
6
×12,

=8+9+2,

=19;

(3)

1
2
×37.5%+
4
5
×
3
8
+
7
10
÷
8
3

=

1
2
×
3
8
+
4
5
×
3
8
+
7
10
×
3
8

=(

1
2
+
4
5
+
7
10
)×
3
8

=(

5
10
+
8
10
+
7
10
)×
3
8

=2×

3
8

=

3
4

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