$\left(-3\right)-\left(+6\right)+\left(+4\right)-\left|\left(-2\right)+\left(-8\right)\right|$

$8\cdot10^{-3}-4\cdot10^{-6}$

$\frac{\left(18-12x\right)}{\left(4x-1\right)\left(x-4\right)}$

$\left(3w+12z\right)\left(3w-12z\right)$

$\int\frac{\sqrt{25-x^2}}{10x^2}dx$

$4\ln\left(x\right)+2\ln\left(y\right)$

$\frac{d}{dx}y=\frac{2senxcosx}{\cos2x}$