$\lim_{x\to\infty}\left(\sqrt{\left(4x^2-6x\right)-2x-1}\right)$

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

$\ln\left(x-1\right)-\ln\left(x+1\right)=\ln\left(x+5\right)$

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

$4-2m-4n$

$21+4x-x^2$

$\int\left(\frac{3x^2+x+2}{x^3-2x^2+2x}\right)dx$