$\left(1-x\right)dy-ydx=0$

$\frac{1+\cos\left(x\right)}{1-\cos\left(x\right)}=\frac{\left(1+\cos\left(x\right)\right)^2}{\sin\left(x\right)^2}$

$\left(3-2i\right)\left(4-i\right)$

$\int\left(\frac{4x-20}{x^2-10x+25}\right)dx$

$\sqrt{3m^4}+4m^3n$

$\lim_{x\to-\frac{1}{2}}\left(\frac{6x-1}{x}\right)$

$\frac{-3x^2-2x+8}{x+2}$