问题 解答题
能简算的要简算.
5
7
×
3
8
+
2
7
×
3
8
4
5
-
2
3
)×15
6
7
÷5+
1
7
×
1
5
答案

(1)

5
7
×
3
8
+
2
7
×
3
8

=(

5
7
+
2
7
)×
3
8

=1×

3
8

=

3
8

(2)(

4
5
-
2
3
)×15

=

4
5
×15-
2
3
×15

=12-10

=2;

(3)

6
7
÷5+
1
7
×
1
5

=

6
7
×
1
5
+
1
7
×
1
5

=(

6
7
+
1
7
)×
1
5

=1×

1
5

=

1
5

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