3. (5 points) A glucose solution is administered intravenously into the bloodstream at a constant rate r. As the glucose is added, it is converted into other substances and removed from the bloodstream at a rate that is proportional to the concentration at that time. A model for the concentration of the glucose solution in the bloodstream is dC =r- 10 where & is a positive constant. Determine the concentration at any time f by solving the differential equation. 4. (5 points) Solve the differential equation: x(y - 1)y = y