\(a,\left(x-1\right)^2+x^2\le\left(x+1\right)^2+\left(x+2\right)^2\\ \Leftrightarrow x^2-2x+1+x^2\le x^2+2x+1+x^2+4x+4\\ \Leftrightarrow2x^2-2x+1\le2x^2+6x+5\\ \Leftrightarrow-8x-6\le0\\ \Leftrightarrow x\ge\dfrac{3}{4}\)
\(b,\left(x^2+1\right)\left(x-6\right)\le\left(x-2\right)^3\\ \Leftrightarrow x^3+x-6x^2-6\le x^3-6x^2+12x-8\\ \Leftrightarrow11x-2\ge0\\ \Leftrightarrow x\ge\dfrac{2}{11}\)
a: \(\Leftrightarrow x^2-2x+1+x^2< =x^2+2x+1+x^2+4x+4\)
=>-2x+1<=6x+5
=>-7x<=4
hay x>=-4/7
b: \(\Leftrightarrow x^3-6x^2+x-6-x^3+6x^2-12x+8< =0\)
=>-11x+2<=0
=>-11x<=-2
hay x>=2/11