Объяснение:
1) 1/x < 1
1/x - 1 < 0
1 - x < 0
-x < -1
x > 1
x ∈ ( 1; +∞)
2) x/(x+3) > 1/2
2x > x + 3
2x - x > 3
x > 3
x ∈ ( 3; +∞)
3) 1/(x+2) < 3(x-3)
x - 3 < 3(x+2)
x - 3 < 3x + 6
x - 3x < 6 + 3
- 2x < 9
x > 9/(-2)
x > -4.5
x ∈ ( -4.5; +∞)
4) 4/(x+1) + 2(1-x) < 1
4/(x+1) - 2(x - 1 ) < 1
4(x - 1) - 2(x+1) < x² - 1
4x - 4 - 2x -2 -x² + 1 < 0
-x² + 2x - 5 < 0
D = 4 - 4*(-1)*(-5) = -16
Нет решений
Объяснение:
1) 1/x < 1
1/x - 1 < 0
1 - x < 0
-x < -1
x > 1
x ∈ ( 1; +∞)
2) x/(x+3) > 1/2
2x > x + 3
2x - x > 3
x > 3
x ∈ ( 3; +∞)
3) 1/(x+2) < 3(x-3)
x - 3 < 3(x+2)
x - 3 < 3x + 6
x - 3x < 6 + 3
- 2x < 9
x > 9/(-2)
x > -4.5
x ∈ ( -4.5; +∞)
4) 4/(x+1) + 2(1-x) < 1
4/(x+1) - 2(x - 1 ) < 1
4(x - 1) - 2(x+1) < x² - 1
4x - 4 - 2x -2 -x² + 1 < 0
-x² + 2x - 5 < 0
D = 4 - 4*(-1)*(-5) = -16
Нет решений