$\left(\frac{a^6+5b^4-b^2}{1}\right)\left(\frac{1}{a^65b^4b^2}\right)$

$3u+9+u$

$\frac{7}{5\:}x\:-\:9.42\:-\:\frac{2}{5\:}x-1.58$

$\int\left(\frac{1}{e^x-e^{-x}}\right)dx$

$\frac{0}{10}$

$\left(2x-5b\right)^3$

$\lim_{x\to0}\left(\frac{1-\cos2\left(x\right)}{\left(1-e^x\right)x}\right)$