$\lim_{x\to\infty}\left(\frac{3x^2+4}{5x^3+9}\right)$

$\int\frac{x^4\left(\sin\left(x^5\right)\right)}{\cos\left(x^5\right)}dx$

$\int\left(\tan\left(x\right)\cdot\left(\sec\left(x\right)+\tan\left(x\right)\right)\right)dx$

$\left(-n+4\right)\left(4n+1\right)$

$15x^2y^3=21x^3y^2$

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

$\lim_{x\to\infty}\left(\frac{4x^3-2x-8}{x^6-6x-2}\right)$