$\lim_{x\to0}\sin\left(x\right)\ln\cos\left(x\right)$

$\frac{sin\left(x\right)}{\cos\left(x\right)+1}+\frac{sin\left(x\right)}{cos\left(x\right)-1}=-\frac{2}{tan\left(x\right)}$

$\log\:_{10}\left(6x-1\right)-\log\:_{10}\left(x+4\right)=\log\:_{10}\left(x\right)$

$15\le x+2$

$\frac{-2000+4\pi r}{r^2}$

$\left(t-9\right)\left(t-5\right)$

$3x\:+\:1\:\ge\:2x\:-\:3$