[tex]\it\Big [x^2+\Big(-\dfrac{4}{3}x^3\Big):\Big(-\dfrac{1}{6}x\Big)\Big]^2:(-3x)^3=\Big(x^2+\dfrac{4x^3}{3}\cdot\dfrac{6}{x}\Big)^2:(-3x)^3=\\ \\ \\ =(x^2+8x^2)^2:(-3x)^3=(9x^2)^2:(-3x)^3 =-\dfrac{81x^4}{27x^3}=-3x[/tex]
