问题 解答题
用简便方法计算下列各题.
①2.84×
3
7
+4.16÷
7
3

②38×
1
4
+17×0.25+45×25%
③0.125×32×2.5
④72×(
5
9
-
5
12
)+10.
答案

①2.84×

3
7
+4.16÷
7
3

=(2.84+4.16)×

3
7

=7×

3
7

=3;

②38×

1
4
+17×0.25+45×25%,

=(38+17+45)×0.25,

=100×0.25,

=25;

③0.125×32×2.5,

=(0.125×8)×(4×2.5),

=1×10,

=10;

④72×(

5
9
-
5
12
)+10,

=72×

5
9
-72×
5
12
+10,

=40-30+10,

=20.

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