$\frac{-x^2-y^2}{-x+y}$

$\left(\frac{1}{3}+x^3\right)\cdot\left(\frac{1}{3}-x^2\right)$

$\frac{cos\left(x-y\right)}{sin\left(x\right)cos\left(y\right)}=cot\left(x\right)+tan\left(y\right)$

$\frac{\left(-x+3\right)}{3}$

$\lim_{x\to\infty}\left(\sqrt{x^2+2x+3}-\sqrt{x^2-2x}\right)$

$\left(w^{\frac{4}{5}}\right)^{\frac{8}{3}}$

$\left(3xy^2\:-\:5\right)^2$