$4-\left(-8-4\right)+\left(-12\right)$

$4\left(x+2\right)-20\left(x-6\right)$

$2=\sqrt{13-3y}$

$\int\frac{x+1}{x\left(x+3\right)\left(x-2\right)}dx$

$100a^{4}-100a^{2}b^{3}+25b$

$9y^4-36$

$\lim_{x\to0}\left(\frac{\arccoth\left(x\right)-x}{x-\sin\left(x\right)}\right)$