$\frac{-1+\csc\left(a\right)\frac{1}{\cos\left(a\right)}\tan\left(a\right)}{\tan\left(a\right)}=\tan\left(a\right)$

$\frac{\:-21^{\:\:15}}{\:\:-21^{\:9}}$

$-2.5+4.4$

$\frac{dy}{dx}=\frac{e^{4x}-3}{e^{2x+3y}}$

$\left(y-16\right)\left(y+20\right)$

$x+59=120$

$\left(7u^3v+4x^4\right)^2$