$\frac{3}{x^2-9}+\frac{x}{x+3}$

$\frac{x^2+x+4}{x-1}$

$\lim_{x\to3}\left(\frac{ln\left(x^2-8\right)}{x^2-9x+18}\right)$

$\int\frac{x^2+4x^2+x-1}{x^3-x^2}dx$

$\int_0^3\left(\frac{1}{\sqrt{1-x^2}}\right)dx$

$-\left(-4-5+6\right)\left(8+12-5\right)$

$\frac{dy}{dx}=12y$