$\left(3y+\right)\left(2y+7\right)$

$\left(6x^2-5x-2\right)^2$

$\left(9+y\right)\left(81-9y+y^2\right)$

$\frac{\csc\:\left(x\right)^2-1}{\csc\:\left(x\right)^2}$

$\sin\left(r+t\right)=\sin\left(r\right)\cos\left(t\right)+\cos\left(r\right)\sin\left(t\right)$

$\frac{d^2}{dy^2}2xy+4x\left(x+y\right)$

$-\left(6-x\right)\left(x-2\right)$