$\left(x+y\right)\left(x-y\right)\left(x^2y^2\right)\left(x^4-y^4\right)$

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

$-x\:-3x\:+\:4y\:+\:6x\:+\:3y\:+\:2x\:-\:6y\:+\:4x\:+x\:-5y$

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

$\frac{2z^2}{3y}x\frac{5z}{7}$

$\lim_{x\to0}\left(\frac{5x^3-4}{x^2+2}\right)$

$8x^2-x+3x-4x^2$