27. - 10, ........., 12 Total numere: 22
28. 12+13+14=39
32. a) 32 elemente
b) 14+15+16+17+18+19=99
33. -15≤2x+3∠20 l - 3
- 15 - 3≤2x∠20 - 3
- 18 ≤ 2x ∠ 17 l : 2
- 18/2 ≤ x ∠ 17/2
- 9 ≤ x ∠ 17/2
a) 18 elemente
b) 0
