$\lim_{x\to1}\left(\frac{2x-1}{\sqrt{x}-1}\right)$

$\sqrt{45x^2}+\sqrt{27x^2}-\sqrt[3]{40x^3}$

$\ln\left(\frac{x}{y}\right)=\ln\left(x\right)-\ln\left(y\right)$

$\frac{8m^{3}-1}{2m-1}$

$\frac{0}{x+1}$

$2^a-3b-5^a-6b+7^a-8b$

$\lim_{x\to\infty}\left(\frac{arctan\left(x^4\right)}{x^8}\right)$