Question

aflati numerele naturale nenule care impartite la 11 dau catul 7.

Answer 1

n-nr. natural 
n=7x11+r                r<7
n=77+r
1. pt. r=0
n=77
2. pt. r=1
n=78
3. pt. r=2
n=79
4. pt. r=3
n=80
5. pt. r=4
n=81
6. pt. r=5
n=82
7. pt. r=6
n=83⇒n∈{77,78,79,80,81,82,83}