用适当的方法计算. 3.5×45+5.5×80%+0.8 &nbsp...

2025-02-23 21:14:02
推荐回答(1个)
回答1:

(1)3.5×
4
5
+5.5×80%+0.8,
=3.5×0.8+5.5×0.8+0.8,
=(3.5+5.5+1)×0.8,
=10×0.8,
=8;

(2)8
4
5
÷[7.8+
1
4
×(2.75+1.25)],
=8
4
5
÷[7.8+
1
4
×4],
=8
4
5
÷[7.8+1],
=8.8÷8.8,
=1;

(3)
4
5
÷[(
3
5
?
1
4
)÷
7
10
],
=
4
5
÷[
7
20
÷
7
10
],
=
4
5
÷
1
2

=
8
5