$\lim_{x\to0}\left(\frac{2x}{x+5\sqrt{x}}\right)$

$45n^2+80n+120=20n^2-20n+20$

$\lim_{x\to-3}\left(\frac{9-x^2}{x+3}\right)$

$7-\left|11-\left(7-13\right)\right|$

$\lim_{x\to0}\left(\frac{\sin\:\left(3x\right)-3x}{3x\sin\:\left(3x\right)}\right)$

$3+\left(10-2\cdot6-3\cdot7\right)$

$\frac{x^3}{x^3-27}$