问题 解答题
用简便方法计算
5-
9
4
÷
45
8
-
3
5

4.9×6.4+14×0.36-6.4×3.5.
答案

(1)5-

9
4
÷
45
8
-
3
5

=5-

9
4
×
8
45
-
3
5

=5-

2
5
-
3
5

=5-(

2
5
+
3
5
),

=5-1,

=4;

(2)4.9×6.4+14×0.36-6.4×3.5,

=(4.9-3.5)×6.4+14×0.36,

=1.4×6.4+14×0.36,

=1.4×6.4+1.4×3.6,

=1.4×(6.4+3.6),

=1.4×10,

=14.

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