How do you write something in algebraic functions?

Question

James has $75 in his bank account, and saves $15 a week. Lee has $330 in her account and withdraws $45 a week.

Write algebraic functions for both James and Lee describing the amount of money y, in the accounts after x weeks.

I'm not sure what to do here... I don't now how to put this in a function.

Answer 1

For James:

He starts with $75 and what changes is how many weeks he saves 15, so the variable will go with the 15

His equation would be: 75+15x=y

The same for Lee, but she subtracts her money since she's withdrawing

330-45x=y