Question

Jana opened a savings account with

$100. She deposited $15 per week. Write

a function that shows the amount in the

account after w weeks.

Answer 1

f(w) = $100 + $15*w

Explanation:

The first $100 she deposited remain always the same, they don't change depending on the weeks. What increases along the weeks are the $15.

In the first week she will deposit $15, so she will have $100 + $15 = $115.

On the second week she will deposit $15 more, so she will have $115 + $15 = $130. Another way of writing this is $100 + $15 + $15 = $100 + $15*2.

On the third week she will have $100 + $15 + $15 + $15 = $100 + $15*3.

Therefore, after w weeks, she will have $100 + $15*w.

The function we are looking for is f(w) = $100 + $15*w