Răspuns:
Explicație pas cu pas:
descopera regula si completeaza sirurile cu inca trei termeni: 5,10,15,....,....,3,6,...,12,.... .....,31,29,27,....,....,.....,20,16,...,8,...,....
5, 10, 15, 20, 25, 30, ....,....,
3,6,9,12, 15, 18, 21,.... .....,
31, 29, 27, 25, 23, 21, ....,....,.....,
20, 16, 12, 8, 4, 0, ...,....