\(-6x^2\left(x+5\right)^2-\left(x-3\right)^2+\left(x^2-2\right)\left(2x^2+1\right)-4x^2\left(3x-4\right)^2\)
\(=-6x^2\left(x^2+10x+25\right)-\left(x^2-6x+9\right)+\left(2x^4-3x^2-2\right)-4x^2\left(9x^2-24x+16\right)\)
\(=-6x^4-60x^3-150x^2-x^2+6x-9+2x^4-3x^2-2-36x^4+96x^3-64x^2\)
\(=-40x^4+36x^3-218x^2+6x-11\)
(đã thử lại)