Răspuns :
7n/7+1/7 = 7n+1/7 subunitara, deci 7n+2<7
22n/11 + 3/11 = 22n+3/11 supraunitara, deci 22n+3>11
rezulta 7n<5 --> n<5/7
22n>8 --> n>8/22 --> n>4/11
22n/11 + 3/11 = 22n+3/11 supraunitara, deci 22n+3>11
rezulta 7n<5 --> n<5/7
22n>8 --> n>8/22 --> n>4/11
(n+1)/7 < 1 => n+1<7
n<6; n∈(-∞,6) si n∈N
(2n+3)/11>1 => 2n+3>11
2n>8 => n>4; n∈(4, +∞) si n∈N
(-∞,6)∩(4, +∞)∩ N = 5
deci, n=5