Ta có: \(-3x\left(x+2\right)^2+\left(x+3\right)\left(x-1\right)\left(x+1\right)-\left(2x-3\right)^3\)
\(=-3x\cdot\left(x^2+4x+4\right)+\left(x+3\right)\left(x^2-1\right)-\left(8x^3-36x^2+54x-27\right)\)
\(=-3x^3-12x^2-12x+x^3-x+3x^2-3-\left(8x^3-36x^2+54x-27\right)\)
\(=-2x^3-9x^2-13x-3-8x^3+36x^2-54x+27\)
\(=-10x^3+27x^2-67x+24\)