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

$\frac{1}{b-1}=\frac{2}{b-2}$

$\frac{x^2+5x-12}{x-3}$

$\left(-\frac{1}{2}a+2u\right)^2$

$f\left(t\right)=\left(t^4-1\right)^3\left(t^3+1\right)^4$

$\frac{d}{dz}\left(x^3z^2-5xy^5z-4y^2=x^2+y^2\right)$

$\lim_{x\to0}\left(\frac{sen\left(y+x\right)-sen\left(y\right)}{x}\right)$