$\frac{1}{2}\cdot6\cdot9$

$\left(-21-54\right)-\left(76+\left(13\right)\right)$

$\frac{dy}{dt}=\left(y+2\right)\left(y-4\right)$

$\frac{\tan\left(y\right)}{\sin\left(2x\right)}y'-\frac{\cos\left(x\right)}{\sec^2\left(y\right)}=0$

$16^2-y^4$

$\left(x+2\right)+\left(x-2\right)\left(2x+1\right)$

$x^2dx+y^2dy=0$