问题 解答题
用简便方法计算:
26×
5
43
+18×
5
43
-
5
43

85×
5
42
答案

(1)26×

5
43
+18×
5
43
-
5
43

=

5
43
×(26+18-1),

=

5
43
×43,

=5;

(2)85×

5
42

=(84+1)×

5
42

=84×

5
42
+1×
5
42

=10+

5
42

=10

5
42

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