$2x^3-3x^2-6x+9-5x^3+2x^2-4x+6$

$\frac{2tan^2x-2}{tan^2x-2tanx+1}$

$\left(-2\right)^3\cdot\left(-3\right)^2$

$\int_{-\frac{x}{4}}^{\frac{x}{6}}\left(-\sec\left(x\right)\tan\left(x\right)\right)dx$

$x^2-8x-6$

$\int x\left(\left(x-1\right)\:\cdot\left(x+2\right)\right)dx$

$-\frac{4}{7}x+\left(-\frac{2}{7}x\right)+\frac{1}{7}$