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

$-4157\:+360$

$\frac{x}{4-x}<3$

$4.9\cdot4.9$

$\frac{36x^4-109x^2+25}{x-3}$

$180x^2-39x-\left(-25x^2\right)$

$\log\left(x+2\right)+\log\left(x-1\right)=\log\left(4\right)$