4x(x-2)≤5;
(2x+1)(x+1)≥3;
3x(1-x)≤-6;
(1-2x)(1-3x)≤2

4x^2 - 8x <= 54x^2 - 8x - 5 <= 04x^2 - 8x - 5 = 0D = 64+80=144 = 12^2x1 = (8+12)/8 = 2,5x2 = (8-12)/8 = -1/22x^2 + x + x + 1 >= 32x^2 + 2x - 2 >= 0x^2 + x - 1 >= 0D = 1 + 4 = 5x1 = (-1 + sqrt5)/2x2 = (-1 - sqrt5)/2