Simon owes $120 for his calculator. He is on a payment plan to pay $10 per week. Write the equasion that relates the number of weeks to the amount owed.

Question

I need an equasion (y=).

 

Answer 1

First assign variables:

 

x = number of weeks

y = amount owed

 

After 0 weeks (in other words, at the start), he owes $120.

 

Every week after that he pays $10, so he reduces the amount owed by $10.  So after x weeks, the amount owed has been reduced by 10 x.

 

So y = 120 - 10 x