1.
2.
__+___[-3]_____-_____[8]____+____
x ∈ [-3;8]
3.
D = 4 + 192 = 196 = 14²
x² = (2 + 14)/6 = 8/3
x₁ = -2√6/3
x₂ = 2√6/3
4.
{y = 4 - 3x
{x² + 16 + 9x² - 24x = 2
{y = 4 - 3x
{10x² - 24x + 14 = 0
D = 576 - 560 = 16
x₁ = (24-4)/10 = 2
x₂ = (24+4)/10=2,8
y₁ = 4 - 6 = -2
y₂ = 4 - 8,4 = -4,4
Ответ: (2; -2) и (2,8; -4,4)
5.
y = (x+2)²
положительно при всех х, кроме х = -2
6.
8.
y ≠ 2; y ≠ -2
3y² - 5y + 2 ≥ 0
D = 25 - 24 = 1
y₁ = (5-1)/6 = 2/3
y₂ = (5+1)/6 = 1
y ≤ 2/3 или y ≥ 1
y∈ (-∞; -2) U (-2; 2/3] U [1; 2) U (2; +∞)
9.
x² + 3x + 2 ≥ 0
D = 9 - 8 = 1
x₁ = (-3-1)/2 = -2
x₂ = (-3+1)/2 = -1
для всех положительных х