1
1; 2
1; 3
1; 2; 4
1; 5
1; 2;
3; 6
1; 7
1; 2;
4; 8
1; 3; 9
1; 2;
5; 10
1
2
3
4
5
6
7
8
9
10
1
4;6;8;9;10
2; 3; 5; 7
280
140
70
35
7
2
2
2
5
7
1
Do đó:
280 =
2.2.2.5.7
= 23.5.7
60
30
15
5
2
2
3
5
1
Do đó:
60 =
2.2.3.5
= 22.3.5
nguon VI OLET