$\left(4x+6\right)\left(3x-3\right)$

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

$4x^2-\left(2x+1\right)^2+4\left(x+1\right)^2+\left(2x+3\right)^2$

$\lim_{x\to\frac{\pi}{4}}\left(6\left(\tan\left(x\right)\right)^{\tan\left(2x\right)}\right)$

$\int x^6\sqrt{x^7+2}dx$

$\lim_{x\to\frac{\pi}{2}}\left(\frac{9\sec\left(x\right)+3}{\tan\left(x\right)}\right)$

$\:9\:-\:1\:+\:5\:+\:6\:-\:3$