$\:\frac{5n^2}{3mn}$

$\int\left(\frac{3}{\left(x+8\right)}\right)dx$

$\int_{\frac{x}{2}}^2\left(sin\:y\:^2\right)dy$

$y=\frac{x^2+x-6}{x^2-4}$

$\frac{sen\left(4x\right)+sen\left(2x\right)}{cos\left(4x\right)-cos\left(2x\right)}$

$\frac{d^2}{dx^2}\left(2x-3y+d\right)$

$\frac{x^3-6x^2+4x-19}{x-3}$