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

$1-\infty^2$

$\lim_{x\to0}\frac{5x^3-4}{x^2-3x+2}$

$\log_{\frac{1}{6}}\left(x^2+x\right)-\log_{\frac{1}{6}}\left(x^2-2\right)=-2$

$\left(1-\sqrt{1-x}\right)\left(1+\sqrt{1-x}\right)$

$\sqrt[3]{\sqrt[6]{\sqrt[4]{\sqrt[5]{5^{-420}}}}}+x^{-1}\cdot\:\sqrt[3]{x^8}\cdot\:\sqrt[3]{x^{-5}}-\sqrt[6]{5^{-7}}-\sqrt[3]{5^{-7}\cdot\:\sqrt[4]{5^{16}}}$

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