$3\left(2-3x\right)+4\left(-3x+1\right)<0$

$2x+1\:+\:2x-1\:area$

$\int\frac{4}{\sqrt{81-x^2}}dx$

$\lim_{x\to0}\left(\frac{2sin\left(x\right)-sin\left(2x\right)}{1-sin\left(x\right)}\right)$

$\left(e^{2y}-y\right)cos\frac{dy}{dx}=e^ysen2x$

$\tan\left(a\right)+\tan\left(b\right)=1$

$\lim_{x\to0}\left(\frac{x^2-6x}{x^2-7x+6}\right)$