$\frac{\left(a+b\right)^2-\left(a-b\right)^2}{ab}$

$\lim_{x\to\infty}\:\frac{2x^2-\:3}{3x^4\:-2x^2\:+5}$

$\int\frac{4x^2-54x+134}{\left(x-1\right)\left(x+5\right)\left(x+3\right)}dx$

$4x+2x^2$

$\frac{\left(n^2-5\cdot\:n^3-1\right)}{n+6\cdot n^3-4}$

$\frac{dy}{dx}\left(xy+2\sqrt{3+y^2}=x^3-2\right)$