$8\left(k+3\right)$

$5\log\:_{10}\left(16-x^2\right)-\left(\log\:_{10}\left(4+x\right)+\log\:_{10}\left(4-x\right)\right)$

$\lim_{x\to0}\left(\frac{1-cosx\:cos3x}{1-cosx}\right)$

$11\left(-20\right)+\left(-31\right)$

$2^2x\:3^3$

$l\:\frac{2\cos\left(2t\right)}{e^{4t}}$

$144h^{14}-36w^{20}$