$\left(3r^3+8m\right)\left(-3r^3+8m\right)$

$\frac{d}{dx}\left(y=\left(x^2+4\right)^{10}\left(2x-5\right)^8\right)$

$m^{10}-100$

$\lim_{x\to2}\frac{\left(x^2-x+6\right)}{x-2}$

$-10x\left(-7\right)x\left(-4\right)$

$\frac{7}{a^2-3a-4}+\frac{2a-5}{a^2-3a-4}$

$\lim_{x\to0}\frac{13tanx-13x}{9x^3}$