$4\left(2x+11-x\right)$

$\frac{x^5+3}{x^3+1}$

$\lim_{x\to2}\left(\frac{x^2-4x+4}{x^2+x-2}\right)$

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

$6x^{2}-xy-2y^{2}\cdot\frac{12x+y}{3}$

$y'\:-xy+\frac{-x}{y}=0$

$\left(\ln\left(y\right)\right)=\ln\left(4x^{x+9}\right)$