$\frac{\left(\sqrt{x^2}-1\right)}{x^3}$

$4+1-2-3+3-1+4-2-1+1+1+5$

$\left(x^{3}-8x^{2}+20x-15\right):\left(x-3\right)$

$\int\:\frac{-3x+4}{4-2x}dx$

$\int\frac{x^3+2x-1}{\left(4x^2+3\right)\left(x^2+4\right)}dx$

$\left(-31\right)\cdot\left(+47\right)$

$x^2+3x+2\:si\:x=2$