$\left(a^2+1\right)\left(a^4+1\right)$

$10m^2n-15mn^2+20mn$

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

$\frac{d^2}{dx^2}\left(\frac{-4}{\left(2+x\right)^2}\right)$

$4x^5-8x^3+6x^2$

$\left(\frac{2}{5}g-2\right)^3$

$x\left(x^2+3x\right)^3$