$\frac{x^2-4x}{x-3}$

$\lim_{x\to0}\left(\frac{1+sen\left(x\right)}{x^3}\right)$

$\int\frac{4x+5}{x^2+4x+20}dx$

$\lim_{x\to\infty}\ln\left(x^2\right)-2\ln\left(x+2020\right)$

$\int\left(sin\left(x\right)^{13}cos\left(x\right)^3\right)dx$

$-3n-10n-2n$

$\frac{36}{3^2}$