6x -9 -6x +4≤1-4x
-5 ≤ 1-4x
1-4x ≥ -5
-4x ≥ -5-1
4x ≤ 6
x ≤ 6/4
x ≤ 1.5
2x²≥2(2x+3)
2x²≥ 4x +6
2x² -4x -6 ≥0
2x² -4x -6 = 0
D = (-4)² -4 2 * (-6) = 64
x1 = (4+8)/4 = 3
x2 =(4-8)/4 = -1
_______+_______-1_______-______3_______+________
x∈ (-∞ ; -1] [-3; +∞)