The question is about advanced function, rational functions. I had some problem to solve my work, I need help.

1. Polluted water flows into a pond. The concentration of pollutant c, in kg/m', in the pond after t minutes is modelled by the equation c(t) = 5t 2500+t Using technology, find out: 1.1. What will happen to the concentration of pollutant over time? 1.2. When will the concentration of pollutant reach a dangerous level of 1 kg/m'? 1.3. When will the concentration of pollutant exceed a critical level of 2 kg/m? Illustrate your investigation by a graph (graphs). (6A, 2C) 2. The concentration c, in mg/L, of a drug in the bloodstream t hours after the drug was taken is given by the equation c(t) = 6t (2 +21+9' Using technology, find out: 2.1. What is the maximum concentration of the drug in the bloodstream and when is it reached? 2.2. What is the concentration of the drug after 1 day? 2.3. When does the concentration exceed one half of its maximum level? Illustrate your investigation by a graph (graphs). (6A, 2C)