1. -20 < x < 21
2. -18 ≤ x ≤ 17
3. -27 < x ≤ 27
4. │x│≤ 3
5. │-x│< 5
6. 1 + (-2) + 3 + (-4) + . . . + 19 + (-20)
7. 1 – 2 + 3 – 4 + . . . + 99 – 100
8. 2 – 4 + 6 – 8 + . . . + 48 – 50
9. – 1 + 3 – 5 + 7 - . . . . + 97 – 99
10. 1 + 2 – 3 – 4 + . . . + 97 + 98 – 99 - 100
Loga
Sinh Học lớp 12
