$19x\left(x-1\right)-18x\left(x-2\right)=12\left(2x-1\right)$

$\frac{7x^4-4x^3+4}{x^3+1}$

$\frac{d}{dx}\left(\frac{x^5\left(x-9\right)^3}{\left(x^2+2\right)^3}\right)$

$\frac{m^4n^5o^6}{m^4n^2o^8}$

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

$^{\left(-x-2\right)^2}$