$\left(\sqrt{6}+\sqrt{2}\right)\left(\sqrt{6}-\sqrt{2}\right)\left(-2xy\right)$

$\lim_{x\to0\:y\:\to\:0}\frac{3xy}{4x^2+5y^2}$

$625-a^4\:b^4$

$\left(-44+18-22\right)\left(-9-11+5\right)$

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

$\int\left(x\right)sin\left(8-x\right)dx$

$2x^2-x^2+8x$