ՏՆԱՅԻՆ․
148.
ա) x – (-2) < 0
x > -2
x ∈ (-2; +∞)
x – (-2) < 0
x + 2 < 0
x < -2
x ∈ (-∞; -2)
x ∈ (-∞; -2) ∩ (−2; +∞)
x ∈ ∅
բ) x + 2 > 0
x > -2
x ∈ (-2; +∞)
x + 2 > 0
x > -2
x ∈ (-2; +∞)
x ∈ (-2; +∞)
Այո։
150․
ա) 3 > x > 1
3 > x > 1
x < 3
x – 3 < 0
x > 1
x – 1 > 0
բ) -1 > x > -3
-1 > x > -3
x < -1
x + 1 < 0
x > -3
x + 3 > 0
152․
ա) 5 > x > 2
x < 5
x – 5 < 0
x > 2
x – 2 > 0
(x – 2)(x – 5) < 0
բ) x < 7
x < 7 < 8
x – 7 < 0
x – 8 < 0
(x – 7)(x – 8) > 0
154․
ա) (x – 1)(x – 3)(x – 4) = 0
⌈x – 1 = 0
|x – 3 = 0
⌊x – 4 = 0
⌈x = 1
|x = 3
⌊x = 4
x ∈ {1, 3, 4}
բ) (x – 1)(x – 3)(x – 4)
4 > 3 > 1 > x
x – 1 < 0
x – 3 < 0
x – 4 < 0
(x – 1)(x – 3)(x – 4) < 0
4 > 3 > x > 1
x – 1 > 0
x – 3 < 0
x – 4 < 0
(x – 1)(x – 3)(x – 4) > 0
4 > x > 3 > 1
x – 1 > 0
x – 3 > 0
x – 4 < 0
(x – 1)(x – 3)(x – 4) < 0
x > 4 > 3 > 1
x – 1 > 0
x – 3 > 0
x – 4 > 0
(x – 1)(x – 3)(x – 4) > 0
(x – 1)(x – 3)(x – 4) > 0
x ∈ (1; 3) ∪ (4; +∞)
(x – 1)(x – 3)(x – 4) < 0
x ∈ (-∞; 1) ∪ (3; 4)
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