$2x+3^3$

$\lim_{x\to-1}\left(\frac{x^3+2x^2+x}{x^3+x^3+x-1}\right)$

$\frac{d}{dx}\left(-\frac{1}{\arctan\left(e^x\right)}\right)$

$2^8\cdot2^2$

$6x\left(6x-y\right)-2\left(y\right)-4$

$\:20\:-\:12\:+\:4x\:-\:4x\:+\:x\:+\:12y\:-\:8y$

$\int y^2cos\left(\frac{y}{a}\right)dy$