$\sqrt{x}e^{x^2}\left(x^2+4\right)^8$

$\left(x+3\right)^2-\left(x-8\right)\left(x+8\right)$

$\frac{3a^5}{4}\cdot\frac{2}{-15a^3}$

$l=1+\frac{1}{1+l}$

$36m^2-81=0$

$\lim_{x\to\frac{-\pi}{4}}\left(\frac{\cos\left(2x\right)}{\cos\left(x\right)+\sin\left(x\right)}\right)$

$m-n+u-3n+4m+5u$