$a-3a+2ac-3bc$

$\int\frac{x+4}{x^2-5x+6}dx$

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

$\int\frac{4}{\left(1+x^2\right)^2}dx$

$\tan\left(x+\left(\frac{3\pi}{2}\right)\right)=-\cot\left(x\right)$

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

$\lim_{x\to\infty}\left(\frac{\left(2x-1\right)^2\left(x+3\right)}{\left(x^3+x+1\right)}\right)$