$e^x\left(x-4\right)=0$

$\int\frac{4x^3+2x^2-x+5}{x}dx$

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

$\lim_{x\to0}\left(\frac{1-e^{-x^2}}{\sin\left(x\right)^2}\right)$

$\frac{dy}{dx}=\frac{-ax}{b+x}$

$\left(x^3-9\right)\left(x^3-2\right)$

$\lim_{x\to2}\left(\frac{4-x^2}{3-sqrt\left(x^2+5\right)}\right)$