$5x-2x^2+x\left(3x-4\right)$

$\lim_{x\to\infty}\left(\frac{3x+1}{2-\sqrt{x^2-4}}\right)$

$-\frac{4}{1}+\frac{12}{1}$

$\frac{d}{dx}\left(2sin3x\:+1\right)$

$\left(5w^2-3w+\frac{4}{5}\right)\cdot\left(-3w^{-3}\right)$

$\lim_{x\to0}\left(\frac{x^5+5x^3}{4x^6+7x^8}\right)$

$-91\:-\:\left(-68\right)$