问题 解答题
怎样简便就怎样算.
(1)3-
7
12
-
5
12
(2)
5
7
×
3
8
+
5
8
×
5
7
(3)18×(
4
9
+
5
6
答案

(1)3-

7
12
-
5
12

=3-(

7
12
+
5
12

=3-1

=2;

(2)

5
7
×
3
8
+
5
8
×
5
7

=

5
7
×(
3
8
+
5
8

=

5
7
×1

=

5
7

(3)18×(

4
9
+
5
6

=18×

4
9
+18×
5
6

=8+15

=23.

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