$\left(-\frac{8}{\left(-5+3\right)}+\frac{12}{\left(-2+2\cdot4\right)}\right)$

$3x^2\cdot\left(2x^3-2x^2+4x-2\right)$

$\frac{2x^2+x-2}{x}$

$\frac{x^2-2x-4}{x-2}$

$\int\left(\frac{e^x}{e^x+5}\right)dx$

$\left(r^6\right)^7$

$\left(4-8\right)\::2-\left(-9\:12\right)\::3$