$\frac{cosx+sinx}{sinx}=cot\left(x\right)+1$

$2.1\cdot2.1$

$\lim_{x\to0}\left(\frac{\left(8^x-7^x\right)}{4^x-3^x}\right)$

$-5\left(3x-2\right)-8x$

$\:\:\int\:\:\left(2-x\right)^3dx$

$\frac{\left(-8\right)^{3}\times\left(-8\right)^{5}}{\left(-8\right)^{2}\times\left(-8\right)^{2}}$

$12\cdot5\cdot\left(-23\right)$