[tex]x^2-\frac{2(x-1)^2}{3}<\frac{(x-1)(x+2)}{3} \ \ |\cdot3\\\\3x^2-2(x-1)^2<(x-1)(x+2)\\\\3x^2-2(x^2-2x+1)<x^2+2x-x-2\\\\3x^2-2x^2+4x-2<x^2+x-2\\\\3x^2-2x^2+4x-x^2-x<-2+2\\\\3x<0 \ \ |:3\\\\x<0\\\\x\in(-\infty;0)[/tex]
