$\left|x\right|^2-\left(4\right)^2$

$log3\left(x+2\right)+log3\left(x+8\right)=3$

$\int\frac{5x^{2}-10x-8}{x^{3}-4x}dx$

$\int\left(\frac{1}{\sqrt{x}\left(\sqrt{x}+1\right)}\right)dx$

$\lim\:_{x\to\:\:1}\left(\frac{x^a-ax+a-1}{\left(x-1\right)^2}\right)$

$4\left(x+y\right)^2-9$

$1=sec^4x-tan^4x$