$\left(-6\right)x^3\cdot7x^2$

$-\left(-9xy\right)\left(-2xy\right)\left(-3x^2y\right)$

$\frac{6x^2+3x}{3x}$

$\lim_{t\to\infty}\left(\frac{\left(ln\left(t\right)\right)^2}{3t}\right)$

$\left(2x+x^2\right)^4-\left(2x-x^2\right)^4$

$\int-8xe^{-2x}\:dx$

$\left(-8-16f\right)+\left(-3f-5\right)$