Question

Susan is putting money into a savings account. She starts with $750 in the savings account, and each week she adds $40.

Let S represent the total amount of money in the savings account (in dollars), and let W
represent the number of weeks Susan has been adding money. Write an equation relating S to W. Then use this equation to find the total amount of money in the savings account after 16 weeks.

Answer 1

s=$750+$40w
s=$750+$40(16)
s=$750+640
s=$1,390

Answer 2

To model this situation, we are going to use the standard linear function:
`y=mx+b`.

1. Since S represent the total amount of money in the savings account,
`y=S`. We also know that each week she adds $40 to her account, so the slope of our linear equation will be
`40W`; therefore,
`m=40W`. Since she started her account with $750,
`b=750`.
Lets replace those values in our linear function:

`y=mx+b`

`S=40W+750`

We can conclude that equation that models this situation is:
`S=40W+750`

2. Now to find the total amount after 16 weeks, we just need to replace
`W` with 16 in our equation and simplify:

`S=40(16)+750`

`S=640+750`

`S=1390`

We can conclude that the amount of money in her account after 16 weeks is $1390