问题
解答题
|
答案
（1）
| 1 |
| 3 |
| 2 |
| 5 |
| 1 |
| 3 |
| 1 |
| 3 |
| 2 |
| 5 |
| 1 |
| 3 |
x=
| 1 |
| 15 |
（2）x-
| 3 |
| 4 |
| 9 |
| 8 |
x-
| 3 |
| 4 |
| 3 |
| 4 |
| 9 |
| 8 |
| 3 |
| 4 |
x=
| 15 |
| 8 |
（3）
| 5 |
| 3 |
| 7 |
| 8 |
| 5 |
| 3 |
| 7 |
| 8 |
| 5 |
| 3 |
| 7 |
| 8 |
| 7 |
| 8 |
| 7 |
| 8 |
x=
| 19 |
| 24 |
搜题请搜索小程序“爱下问搜题”
|
（1）
| 1 |
| 3 |
| 2 |
| 5 |
| 1 |
| 3 |
| 1 |
| 3 |
| 2 |
| 5 |
| 1 |
| 3 |
x=
| 1 |
| 15 |
（2）x-
| 3 |
| 4 |
| 9 |
| 8 |
x-
| 3 |
| 4 |
| 3 |
| 4 |
| 9 |
| 8 |
| 3 |
| 4 |
x=
| 15 |
| 8 |
（3）
| 5 |
| 3 |
| 7 |
| 8 |
| 5 |
| 3 |
| 7 |
| 8 |
| 5 |
| 3 |
| 7 |
| 8 |
| 7 |
| 8 |
| 7 |
| 8 |
x=
| 19 |
| 24 |
设有关系R，S和T如下图。关系T由关系R和S经过( )操作得到。
R
| A | B | C |
| 1 2 3 4 1 6 3 2 4 | ||
| A | B | C |
| 4 1 6 2 7 1 | ||
| A | B | C |
| 1 2 3 2 2 4 | ||
A．R∪S
B．R-S
C．R×S
D．R∞S