$\lim\:_{x\to\:\:5}\left(\frac{x^2-5x+6}{x-5}\right)$

$-16sin\left(x\right)=0$

$\lim_{x\to1}5x\left(1+x\right)$

$5\left(-2\right)^2\left(-1\right)-8\left(3\right)\left(-\frac{1}{2}\right)$

$\frac{2160}{72}$

$\frac{cot\left(x\right)+csc\left(x\right)}{cot\left(x\right)}-2=0$

$x^8-2x^7-x^6$