$\lim_{x\to0}\left(\frac{x^3+4x^2+4x}{x^2-4x}\right)$

$-2x^4x^3$

$\int_{\frac{\pi}{12}}^{\frac{\pi}{8}}\left(\cot^3\left(2y\right)\right)dy$

$\left(9x+5\right)^2$

$\frac{1}{4}y^2-\frac{3}{8}y^2-y^2$

$\lim_{x\to3}\left(\frac{x^2-9}{-6x-18}\right)$

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