(2x-1)^3\geq 2x(2x-\frac{3}{2})^2+17
źródło:
8x^3-12x^2+6x-1\geq 2x(4x^2-6x+2,25)+17
8x^3-12x^2+6x-1\geq 8x^3-12x^2+4,5x+17
8x^3-2x^2+6x-8x^3+12x^2-4,5x\geq 1+17
1,5x\geq 18/:6
x\geq12
Odp.
x\in<12;\infty)