$\frac{8x^6y}{4x^3y^2}$

$\left(4-9-\left(-7\right)\right)-\left(12-4+\left(-22\right)\right)$

$a^2+b^2=6$

$-47=g-52$

$2cosx\:=\:3tgx$

$\sec\left(\theta\right)-tan\left(\theta\right)=\:\frac{cos\left(\theta\right)}{1+sin\left(\theta\right)}$

$\lim_{x\to2\pi}\left(\frac{\sin\left(x\right)-\sin\left(2\pi\right)}{x-2\pi}\right)$