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Homework Help: Differential Equation

  1. Oct 22, 2007 #1
    1. You have a bank account that earns 4% interest per year. You earn $4500 per year designing web pages for local businesses and spend $5000 buying CD's and computer games.
    a.) Find differential equation that models account t years from now, A(t). b) If A(0) = 10,000 how much money will be in the account in 5 years?

    2. Relevant equations

    3. a. dA/dt = 4500t - 5000t b. 10000(1.04)^5 + 4500*5 - 5000*5. Is this correct? The problem for part b is that I can't use a calculator and the problem gives me a hint that e^(1/5) = 6/5/
  2. jcsd
  3. Oct 22, 2007 #2


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    Staff Emeritus
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    You've not used the 4% interest yet though. That says that every year 4% of your money will be added on. Can you add this into the differential equations?
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