Answer:
[tex]y=200-25x[/tex]
Step-by-step explanation:
According to the problem, the initial condition is $200. If he owed $100 after 4 weeks, that means he paid $25 per week, so that would be the constant ratio. Therefore, the expression would be:
[tex]y=200-25x[/tex]
Where [tex]y[/tex] represents the amount owed, and [tex]x[/tex] represents weeks.
So, in the 4 week, that is, [tex]x=4[/tex] he owed:
[tex]y=200-25(4)=200-100=100[/tex]
As you can observe, the relation we found first perfectly to the problem. So, the final expression that model this problem is
[tex]y=200-25x[/tex]