$\:\frac{4x-6}{6\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:}\le-5$

$\frac{dy}{dx}-y=5e^x$

$\int\left(\frac{e^{3x}-e^x}{e^x+1}\right)dx$

$\sqrt[14]{27^{12}}\cdot243^4$

$\lim_{x\to0}\left(\frac{\tan^35x}{x^2\sin4x}\right)$

$\left(1-\cot a^2\right)$

$\int\frac{\arctan\left(\frac{x}{2}\right)}{4+x^2}dx$