Question

Alberto opens a bank account with $120 and puts $6 into the account each week. a. Write a function to represent the amount of money in the account after w weeks. b. How many weeks will it take for Alberto to have $252 in the account?

Answer 1

The amount of money in Alberto's account shall be represented by a.

The first money paid in is 120, and then every week he adds another 6 into the account. If the weeks are represented by w, then the function to show how much he has is;

`a=120+6w`

This because, each week, he would add 6, so in the first week, it would be 6(1), in the second week it would be 6(2), in the third week it would be 6(3), and so on.

(b); How many weeks will it take for Alberto to have $252 in the account?

We shall calculate this by inputting the known value, which is the total amount after the unknown number of weeks, as follows;

`\begin{gathered} a=120+6w \\ \text{This now becomes;} \\ 252=120+6w \\ \text{Subtract 120 from both sides} \\ 252-120=120-120+6w \\ 132=6w \\ \text{Divide both sides by 6} \\ 22=w \end{gathered}`

The results show that it would take him 22 weeks to have $252 in his account