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

$19+24-\left(-31\right)$

$-0.1\left(70\right)^3+0.6\left(70\right)^2+85$

$\left(2x+4y\right)^3\:\:$

$\frac{d^2}{dx^2}\left(\frac{\pi}{2}\right)$

$\left(3a^5+5\right)\left(3a^5+9\right)$

$4x\:+7\:y\:-\:42\:=\:0\:$