作业帮 > 数学 > 作业

合理、灵活地计算①45

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/07/08 11:44:54
合理、灵活地计算
4
5

4
5×3.5+5.5×80%+0.8,
=0.8×3.5+5.5×0.8+0.8,
=(3.5+5.5+1)×0.8,
=10×0.8,
=8;
②(
7
17×19-
7
17)×
17
18,
=[(19-1)×
7
17]×
17
18,
=18×
7
17×
17
18,
=7;
③1
5
6÷[
6
11×(
5
9-
1
4)],
=
11
6÷[
6
11×
11
36],
=
11

1
6,
=
11
6×6,
=11;
④2.35÷[4.75-4.5×(0.2+
1
3)],
=2.35÷[4.75-4.5×(
1
5+
1
3)],
=2.35÷[4.75-4.5×
8
15],
=2.35÷[4.75-2.4],
=2.35÷2.35,
=1.