Question

va rog ex 30 dau coroana si multe puncte

Answer 1

12=3*4
15=3*5
3,4,5 prime intre ele oricare 2
[3,4,5]=3*4*5=60


2n+1∈{1;3;5;15}
2n∈{0;2;4;14}
n∈{0;1;2;7}
as simple as that!!!
(dar Nu de sc.primara!!)

Answer 2

2n divide pe 14
n={1, 7}