fie k|8n+3 si k|5n+8
atunci k |5* (8n+3), k|40n+15
si
k| 8(5n+8) k|40n+64
k|40n+64-40n-15
k|49
k=1 nu are sens pt simplificare
k=7 sau k|7p
5n+8=7, n∉N
5n+8=14,n∉N
5n+8=21, n∉N,
5n+8=7*4=28 n=4∈N
totodata si 8*4+3=35 si 7|35
deci cm.m mic n=4
28/35=4/5
pt k=49 sau k|49p rezulta numere mai mari