Stabiliti valoarea de adevăr a propoziţiilor:
a 12 € (10.11.12);
d{2, 3, 6, 8}\{5, 2, 1, 3} = {6,8};
(1.8.10.15) = {8, 1, 10; e 6 €{2, 5, 6, 7}, {4, 1, 6, 8, 10}.
- 17 e 13.15.17.19};
f17 € {13, 14, 15, ..., 21} , {2, 4, 6, ..., 32). Va rog urgent!!​