$\frac{x^2+12}{x^2+4}$

$\frac{dy}{dx}=\frac{e^{-y}}{e^xy}$

$\int_0^{\infty}\left(\frac{ln\left(x\right)}{x^{k+1}}\right)dx$

$\left(-2x^3+5x^2+2\right)-\left(8x^3+4x^2-5\right)$

$\lim_{x\to2}\left(\frac{x+2}{x^2}\right)^{\frac{x-1}{x-2}}$

$\int7\sin^2\left(5x\right)dx$

$2x+9x^2$