521×27+21921×57+(1−27)
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/06/04 21:38:26
5 |
21 |
2 |
7 |
19 |
21 |
5 |
7 |
2 |
7 |
5
21×
2
7+2
19
21×
5
7+(1-
2
7),
=
5
21×
2
7+2
19
21×
5
7+
5
7,
=
5
21×
2
7+(2
19
21+1)×
5
7,
=
5
21×
2
7+
82
21×
5
7,
=
2
21×
5
7+
82
21×
5
7,
=(
2
21+
82
21)×
5
7,
=4×
5
7,
=
20
7.
21×
2
7+2
19
21×
5
7+(1-
2
7),
=
5
21×
2
7+2
19
21×
5
7+
5
7,
=
5
21×
2
7+(2
19
21+1)×
5
7,
=
5
21×
2
7+
82
21×
5
7,
=
2
21×
5
7+
82
21×
5
7,
=(
2
21+
82
21)×
5
7,
=4×
5
7,
=
20
7.