Răspuns:
Explicație pas cu pas:
6.
a)
2/x/ ≤ 8
/x/ ≤ 4
x = [-4, 4]
_________
b)
-6 < 2x - 3 < 6
-3 < 2x < 9
-3/2 < x < 9/2
x = (-3/2, 9/2)
__________
c)
-√2 ≤ x + 2 ≤ √2
-√2 - 2 ≤ x ≤ √2 + 2
[-√2 - 2, √2 + 2]
_______________
7.
-5 ≤ (7x + 4)/2 < 16
-10 ≤ 7x + 4 < 32
-14 ≤ 7x < 28
-2 ≤ x < 4
A = [-2, 4)
-8 ≤ 5x - 2 ≤ 8
-6 ≤ 5x ≤ 10
-6/5 ≤ x ≤ 2
B = [-6/5, 2]
A U B = [-2, 4)
A ∩ B = [-6/5, 2]
A ∩ Z = {-2, -1, 0, 1, 2, 3}
B ∩ N = {0, 1, 2}
_______________
9.
/x/ > 3
A = (-∞, -3) U (3, + ∞)
____
/x + 1/ > 2
B = (- ∞, -3) U (1, + ∞)
_____
/x/ ≤ 0
C = {0}
