## anonymous 5 years ago solve for u: du/dt = 2(5-u).

$$\int du/(5-u)=\int 2 dt$$ $$-\ln|5-u|=2t+C$$ $$\ln|5-u|=-2t+C$$ $$|5-u|=Ae^{-2t}$$ (where $$A$$ is just another constant) $$5-u=\pm Ae^{-2t}$$ $$u=5\pm A e^{-2t}$$