$\frac{d}{dx}5^{-3x}cot^{-1}\left(8x\right)$

$\lim_{x\to\infty}\left(\frac{e^{\frac{x}{15}}}{x}\right)$

$16\left[\left(16-7\right)\cdot3-25\right]$

$\left(-9x+2x^2\right)^2$

$\left(t+s+4\right)\left(t+s-4\right)$

$y=-3x^{-3}-2x^{-2}$

$\frac{2-\tan\left(x\right)}{2csc\left(x\right)-\sec\left(x\right)}$