$x^2+5x+19;x=-3$

$\int x\left(6x+5\right)dx$

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

$\:\frac{z^2-9z}{z^2+3z-4}\cdot\:\frac{5z+3}{z^2+3z-4}$

$\frac{x^3-22x^2+15}{x+5}$

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

$\frac{\left(3x^4-18x^2-9x+6\right)}{x^2+3x+2}$