$\lim_{x\to\infty}\left(\frac{x^2+\sqrt{x}-17}{23x^2-2x^5+\frac{1}{x}}\right)$

$\frac{18y^9}{6y^5}$

$\int\left(x^2+x\right)^{14}\left(2x+1\right)\:dx$

$\left(7b-3\right)\left(7b+3\right)$

$\int\left(x\left(1-cos2x\right)\right)dx$

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

$\int e^{-4x}sen5xdx$