its a question from mathematical modeling..been having problems with these two...any help?

Your credit card balance is N$ 12 000 with a current rate of 19.9% per year. Interest is charged monthly. Determine what monthly payment will pay off the card in 4 years, assuming no new charges. (6) 3. Your credit card balance is NS 12 000 with a current rate of 19.9% per year. Interest is charged monthly. Determine what monthly payment will pay off the card in 4 years, assuming no new charges. (6) 4. Suppose the spotted owls primary food source is the mice. An ecologist wishes to predict the population levels of spotted owls and mice in a wildlife sanctuary. Letting Me represents the mice population after n years and on the predator owl population, the ecologist suggested the following model. M +1 = 1.2M, -0.0010,M, On+1 = 0.70, +0.0020, M The ecologist wants to know if the two species can coexist in the habitat and if the outcome is sensitive to the starting initial) populations. (a) Find the equilibrium points of the system. (b) Test the initial populations in the table below by building up numerical solutions and predict the long-term outcome. (15) Cases Mice Owls A 300 150 B 200 100 20 10 D 200 150