问题 解答题
4
7
×
1
4
+0.25×
3
7
-
1
4
答案

4
7
×
1
4
+0.25×
3
7
-
1
4

=

4
7
×
1
4
+
1
4
×
3
7
-
1
4

=

1
4
×(
4
7
+
3
7
-1),

=

1
4
×(1-1),

=0.

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