$\frac{\left(4x^3\right)^2}{\left(121\left(-1\right)x^5\right)^3}$

$x^2+9x-20$

$\left(x-8\right)\left(x-4\right)$

$\sqrt{1-2\cdot senx\cdot cosx}$

$\log\left(\frac{x^2}{x-6}\right)=0$

$\left(5y+2m\right)^2$

$\tan\left(a+b\right)-\tan\left(a\right)$