To model this situation, we are going to use the standard linear function:
.
1. Since S represent the total amount of money in the savings account,
. We also know that each week she adds $40 to her account, so the slope of our linear equation will be
; therefore,
. Since she started her account with $750,
.
Lets replace those values in our linear function:
We can conclude that equation that models this situation is: 2. Now to find the total amount after 16 weeks, we just need to replace
with 16 in our equation and simplify:
We can conclude that the amount of money in her account after 16 weeks is $1390