$\frac{5a^3}{a}$

$\frac{dy}{dx}=\frac{1}{10}$

$-3x^2y+12xy^2$

$\left(x^4-\frac{5}{2}x^3-\frac{1}{2}x^2+11x-3\right)\left(3x+3\right)\:+11$

$\frac{dy}{dx}=-\frac{2x+3y+1}{3x+4y+1}$

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

$\frac{dy}{dx}=\frac{1-x^2+y^2-x^2y^2}{x^2}$