



 
Hello Iona. I can get you started on this problem. Think of time (the number of months after graduation) as the horizontal axis and debt (the loan balance) as the vertical axis. If M is the number of months and B is the balance owing then there are several things we can say in order to come up with the equation.
So B starts at $6000, but you subtract $350 for every M. That means you subtract M times $350. So
Now graph this relationship. If it helps you sort things out, you can replace it with
which is the same thing if y is the balance owing and x is the number of months since graduation. Look at the graph carefully and you'll be able to answer parts (3) and (4). Hope this helps,  


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