$\left(7x^3y-2z\right)\left(7x^3y+2z\right)$

$\frac{d}{dx}\left(4x^3+6\right)\left(\sqrt{x}+8\right)$

$u\:2\:-\:4u\:-\:60$

$\left(x-.5\right)\left(x-3\right)$

$\left(2x+3\left(2x-3\right)\right)$

$\lim\:_{x\to\:\infty}\left(xtan\left(\frac{12}{x}\right)\right)$

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