$\frac{dy}{dx}\left(\frac{y-1}{x+3}\right)$

$\frac{z^{2-5z+4}}{z^2-6z+5}$

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

$64x^2-96xy+36y^2$

$\lim_{x\to\infty}\left(\frac{x^3-6x^2+9x+7}{2-4x}\right)$

$\lim_{x\to\infty}\left(x^3-x\right)$

$\left(2+3x\right)\left(2b+z+4\right)$