Question Number 1804 by 123456 last updated on 03/Oct/15
$$\left(\mathrm{1}−{u}\right)\frac{\partial{u}}{\partial{t}}={u}\frac{\partial{v}}{\partial{t}} \\ $$$$\left(\mathrm{1}−{v}\right)\frac{\partial{v}}{\partial{t}}={v}\frac{\partial{u}}{\partial{t}} \\ $$$$\frac{\partial}{\partial{t}}\left({uv}\right)=? \\ $$