$2\pi\int_0^1\left(e^{-x}\right)\sqrt{1+e^{-2x}}dx$

$\left(-7\right)-\left\{9-\left[\left(-7\right)+\left(-13\right)-\left(-5\right)\right]+\left[23-\left(18\right)+\left(-6\right)\right]\right\}$

$2\log\left(x-2\right)=\log\left(x-2\right)$

$\left(xy-y\right)^3$

$\frac{36m^{-4}n^6}{4mn^{-2}p^{-4}}$

$\sqrt[3]{27ab^3}-\sqrt[3]{64a^3b}-\sqrt[3]{216ab^3}$

$a+b+c-a-b-c$